; ****************************************************************************** ; Copyright © [05/15/1999] Scenix Semiconductor, Inc. All rights reserved. ; ; Scenix Semiconductor, Inc. assumes no responsibility or liability for ; the use of this [product, application, software, any of these products]. ; Scenix Semiconductor conveys no license, implicitly or otherwise, under ; any intellectual property rights. ; Information contained in this publication regarding (e.g.: application, ; implementation) and the like is intended through suggestion only and may ; be superseded by updates. Scenix Semiconductor makes no representation ; or warranties with respect to the accuracy or use of these information, ; or infringement of patents arising from such use or otherwise. ;****************************************************************************** ; ; Filename: v_23_originate_1_37.src ; ; Author: Chris Fogelklou ; Applications Engineer ; Scenix Semiconductor Inc. ; ; Revision: 1.37 ; ; Part: SX28AC datecode 9929AA/ SX52BD datecode AB9919AA ; Freq: 50Mhz ; ; Compiled Using: SX-Key v.1.07 and SASM V. 1.43 ; ; Date: May 23, 1999. ; ; Revised November 30, 1999 ; ; Program Description: ; This program performs V.23 origination on the Scenix/IDC ; modem boards V.1.2. These specifications are followed: ; ; User Interface ; - Software UART will provide the modem’s interface. ; - 1200 baud ; - No Parity ; - 8 Data Bits ; - 1 Stop Bit ; - Hardware Flow Control (CTS, RTS) ; - Compact AT command set ; - 64-byte command buffer ; - Dial: “ATDTxxxxxxxxx…” ; - Switch from data mode to command mode: “+++” ; To escape, wait at least 3 seconds from the last transmitted ; character, and type +++ with less than 1 second between each ; character. The modem will return to command mode if another ; character is not received in 3 seconds. ; - Switch from command mode to data mode: “ATO” ; - Hang up: “ATH” ; - Initialize: “ATZ” ; - Automatic Hybrid Adjustment: “ATY” ; ; Signal Generation/Detection Software ; - DTMF Generation for Dialing ; - Tones generated: 697Hz, 770Hz, 852Hz, 941Hz, 1209Hz, 1336Hz, 1477Hz,1633Hz ; - On time = 100ms ; - Off time = 100ms ; - Off-hook delay time before dialing = 4 s ; - D/A conversion provided by filtered PDM output ; - Data transmission and modulation ; - FSK transmission data rate at 75bps ; - Hardware flow control, 16-byte buffer, and 75bps asynchronous transmitter for ; data rate conversion from 1200bps to 75bps ; - Logic ‘1’ (mark) modulated by 390 Hz ; - Logic ‘0’ (space) modulated by 450 Hz ; - Transmission power = -15dB ; - D/A conversion provided by filtered PDM output ; - Data reception and demodulation ; - FSK reception data rate at 1200bps ; - Logic ‘1’ (mark) demodulated from 1300Hz carrier ; - Logic ‘0’ (space) demodulated from 2100Hz carrier ; - Carrier detection ; - Timed-Zero-Cross algorithm ; - D/A conversion ; - Pulse Position Modulation with maximum output frequency of 307kHz ; ; Hardware Specifications ; - Filtering ; - Low pass filter on PDM output (fc = 1633Hz) ; - High pass filter on FSK input (fc = 1300Hz) ; - Hybrid (removes tx signal from rx signal) ; - Four settings provided for automatic hybrid adjustment for various line ; impedance’s ; - Hybrid adjusted by outputting signal onto line and measuring fed-back signal ; with a low-resolution sigma-delta A/D converter ; - FSK input sensitivity = -30dB ; - Auto-Hybrid removed in V.1.37 ; - UART ; - RS-232 interface provided through MAX232 or similar IC ; - Interface provided through RXD, TXD, RTS, and CTS lines ; ; Testing Specifications ; - Initial tests using function generator and off-the-shelf V.23 modems ; - Second round of testing performed with IDC’s modem test equipment ; - Tests performed: ; - Input Sensitivity ; - DTMF output level ; - FSK output level ; - Error rate ; - FCC part 68 and FCC part 15 qualified ; - CTR-21 ready ; - All test results will be documented ; ; Program Instructions; ; To use this program, the modem board must be connected to a serial port at ; these settings: ; 1200 bps ; No parity ; 8 Data Bits ; 1 stop bit ; Hardware flow control ON!!! (CTS/RTS) ; ; These AT commands can be used: ; ; ATDT - Used to dial into a remote modem ; ATH - Used to hang up a call ; ATZ - Used to initialize the modem settings ; ATO - Switches back to data mode from command mode ; +++ - Switches from data mode to command mode. ; ? - Re-prints the help screen to the terminal. ; ; Revision History: ; 1.10 Took semi-working V.23 code and cleaned it up. Kept it working, but made ; few improvements to the operation. ; 1.15 Finally got FSK receive to work error free!!! Whooopeee!!! ; 1.17 Added documentation. ; 1.20 Added carrier detection to the software ; 1.30 Added automatic hybrid adjustment to the software. ; 1.32 Automatic hybrid adjustment tweaked until working. Component values for A/D: ; C = 470pF, R1 = 22k, R2 = 10k ; 1.35 Added guard times around the “+++” coming in. ; 1.37 Removed Auto-Hybrid Adjust. Made sure assembly worked in SASM. ; Removed CARRYX directive and modified source code accordingly. ; ; ; RESOURCES: ; Program memory: TBD ; Data memory: TBD ; I/O Count: TBD ; ;***************************************************************************************** ; Target SX ; Uncomment one of the following lines to choose the SX18AC, SX20AC, SX28AC, SX48BD/ES, ; SX48BD, SX52BD/ES or SX52BD. For SX48BD/ES and SX52BD/ES, uncomment both defines, ; SX48_52 and SX48_52_ES. ;***************************************************************************************** ;SX18_20 SX28 ;***************************************************************************************** ; Assembler Used ; Uncomment the following line if using the Parallax SX-Key assembler. SASM assembler ; enabled by default. ;***************************************************************************************** SX_Key ;********************************************************************************* ; Assembler directives: ; high speed external osc, turbo mode, 8-level stack, and extended option reg. ; ; SX18/20/28 - 4 pages of program memory and 8 banks of RAM enabled by default. ; SX48/52 - 8 pages of program memory and 16 banks of RAM enabled by default. ; ;********************************************************************************* IFDEF SX_Key ;SX-Key Directives IFDEF SX18_20 ;SX18AC or SX20AC device directives for SX-Key device SX18L,oscxt4,turbo,stackx_optionx ENDIF IFDEF SX28 ;SX28AC device directives for SX-Key device SX28L,oscxt4,turbo,stackx_optionx ENDIF freq 50_000_000 ELSE ;SASM Directives IFDEF SX18_20 ;SX18AC or SX20AC device directives for SASM device SX18,oschs1,turbo,stackx,optionx ENDIF IFDEF SX28 ;SX28AC device directives for SASM device SX28,oschs1,turbo,stackx,optionx ENDIF ENDIF ID 'v23org13' ; Version = 1.1 reset reset_entry ; JUMP to reset_entry label on reset ;***************************************************************************************** ; Macros ;***************************************************************************************** ;********************************************************************************* ; Macro: _bank ; Sets the bank appropriately for all revisions of SX. ; ; This is required since the bank instruction has only a 3-bit operand, it cannot ; be used to access all 16 banks of the SX48/52. For this reason FSR.4 (for SX48/52BD/ES) ; or FSR.7 (SX48/52bd production release) needs to be set appropriately, depending ; on the bank address being accessed. This macro fixes this. ; ; So, instead of using the bank instruction to switch between banks, use _bank instead. ; ;********************************************************************************* _bank macro 1 bank \1 IFDEF SX48_52 IFDEF SX48_52_ES IF \1 & %00010000 ;SX48BD/ES and SX52BD/ES (engineering sample) bank instruction setb fsr.4 ;modifies FSR bits 5,6 and 7. FSR.4 needs to be set by software. ENDIF ELSE IF \1 & %10000000 ;SX48BD and SX52BD (production release) bank instruction setb fsr.7 ;modifies FSR bits 4,5 and 6. FSR.7 needs to be set by software. ELSE clrb fsr.7 ENDIF ENDIF ENDIF endm ;********************************************************************************* ; Macro: _mode ; Sets the MODE register appropriately for all revisions of SX. ; ; This is required since the MODE (or MOV M,#) instruction has only a 4-bit operand. ; The SX18/20/28AC use only 4 bits of the MODE register, however the SX48/52BD have ; the added ability of reading or writing some of the MODE registers, and therefore use ; 5-bits of the MODE register. The MOV M,W instruction modifies all 8-bits of the ; MODE register, so this instruction must be used on the SX48/52BD to make sure the MODE ; register is written with the correct value. This macro fixes this. ; ; So, instead of using the MODE or MOV M,# instructions to load the M register, use ; _mode instead. ; ;********************************************************************************* _mode macro 1 IFDEF SX48_52 mov w,#\1 ;loads the M register correctly for the SX48BD and SX52BD mov m,w ELSE mov m,#\1 ;loads the M register correctly for the SX18AC, SX20AC ;and SX28AC ENDIF endm ;***************************************************************************************** ; Error generating macros ;***************************************************************************************** tableStart macro 0 ; Generates an error message if code that MUST be in ; the first half of a page is moved into the second half. if $ & $100 ERROR 'Must be located in the first half of a page.' endif endm tableEnd macro 0 ; Generates an error message if code that MUST be in ; the first half of a page is moved into the second half. if $ & $100 ERROR 'Must be located in the first half of a page.' endif endm ;***************************************************************************************** ; Data Memory address definitions ; These definitions ensure the proper address is used for banks 0 - 7 for 2K SX devices ; (SX18/20/28) and 4K SX devices (SX48/52). ;***************************************************************************************** IFDEF SX48_52 ERROR ' This program has not been ported to SX48/52' ; Let the programmer know that this program ; will only work on the SX28. ELSE global_org = $08 bank0_org = $10 bank1_org = $30 bank2_org = $50 bank3_org = $70 bank4_org = $90 bank5_org = $B0 bank6_org = $D0 bank7_org = $F0 ENDIF ;***************************************************************************************** ; Global Register definitions ; NOTE: Global data memory starts at $0A on SX48/52 and $08 on SX18/20/28. ;***************************************************************************************** org global_org flags ds 1 dtmf_gen_en equ flags.0 ; Signifies whether or not DTMF output is enabled sine_gen_en equ flags.1 ; Enables the sine generator(s) for DTMF generation and ; FSK generation timer_flag equ flags.2 ; Set every time the timers roll over. fsk_tx_en equ flags.3 ; enables the fsk transmission portion of the ISR fsk_rx_en equ flags.4 ; enables the fsk reception portion of the ISR rx_flag equ flags.5 ; this flag is set when a byte is received via the UART fsk_rx_bit equ flags.6 ; this bit indicates the current state of the FSK being carrier_detected equ flags.7 ; indicates the presence of a carrier ; received. flags2 ds 1 swCarryFlag equ flags2.0 temp ds 1 ; Temporary register temp2 ds 1 ; Temporary register task_switcher ds 1 ; Used in the ISR to switch between tasks. push_index ds 1 ; Used by the 64-byte buffer to store bytes. pop_index ds 1 ; Used by the 64-byte buffer to retrieve bytes. command_index ds 1 ; Used by the string parser to remember the current ; command being checked. ;****************************************************************************** ; Bank 0 Variables ;****************************************************************************** org bank0_org sine_gen_bank = $ freq_acc_low ds 1 ; 16-bit accumulator which decides when to increment the sine wave freq_acc_high ds 1 ; freq_count_low ds 1 ; 16-bit counter which decides which frequency for the sine wave freq_count_high ds 1 ; freq_count = Frequency * 6.83671552 sine_index ds 1 ; Index into the sine table for sine wave 1 sine_index2 ds 1 ; Index into the sine table for sine wave 2 freq_count_low2 ds 1 ; 16-bit counter which sets the sine wave frequency freq_count_high2 ds 1 ; freq_count = Frequency * 6.83671552 freq_acc_high2 ds 1 ; freq_acc_low2 ds 1 ; 16-bit accumulator which decides when to increment the sine wave curr_sine ds 1 ; The current value of the sine wave curr_sine2 ds 1 ; The current value of sine wave 2 sine2_temp ds 1 ; This register is used to do a temporary shift/add register PDM_bank = $ PDM0_acc ds 1 ; PDM accumulator PDM0_out ds 1 ; current PDM output (D/A) ;****************************************************************************** ; Bank 1 Variables ;****************************************************************************** org bank1_org timers = $ timer_l ds 1 ; The low byte of the 24-bit timer timer_h ds 1 ; the middle byte of the 24-bit timer timer_hh ds 1 ; the high byte of the 24-bit timer serial = $ ;UART bank tx_high ds 1 ;hi byte to transmit tx_low ds 1 ;low byte to transmit tx_count ds 1 ;number of bits sent tx_divide ds 1 ;xmit timing (/16) counter rx_count ds 1 ;number of bits received rx_divide ds 1 ;receive timing counter rx_byte ds 1 ;buffer for incoming byte rx_count2 ds 1 ;number of bits received rx_divide2 ds 1 ;receive timing counter rx_byte2 ds 1 ;buffer for incoming byte string ds 1 ;the address of the string to be sent byte ds 1 ;semi-temporary serial register plus_count ds 1 ;stores the number of consecutive '+''s received during ; FSK i/o mode. ;****************************************************************************** ; Bank 2 Variables ;****************************************************************************** org bank2_org fsk_transmit_bank = $ fsk_receive_bank = $ fsk_serial_bank = $ fsk_tx_high ds 1 ;hi byte to transmit fsk_tx_low ds 1 ;low byte to transmit fsk_tx_count ds 1 ;number of bits sent fsk_tx_divide ds 1 ;xmit timing (/16) counter fsk_tx_divide_2 ds 1 fsk_trans_count ds 1 ; This register counts the number of counts ; between transitions at the pin fsk_last_trans ds 1 fsk_rb_past_state ds 1 ; This register keeps track of the previous ; state of port RB, to watch for transitions fsk_temp_trans ds 1 ; Temporarily stores the transition count after ; a transition has occurred, until it can be processed. fsk_flags ds 1 fsk_answering equ fsk_flags.0 fsk_tx_bit equ fsk_flags.1 fsk_processing_required_1 equ fsk_flags.2 ;****************************************************************************** ; Bank 3 Variables ;****************************************************************************** org bank3_org carrier_detect_bank = $ cd_trans_count ds 1 cd_trans_avg_l ds 1 cd_trans_avg_h ds 1 cd_avg_count ds 1 cd_rb_past_state ds 1 ;************************************************************* ; Bank 4, 5, 6, 7 (for 64-byte buffer, but can be reused.) ;************************************************************* org bank4_org buffer = $ org bank5_org buffer2 = $ org bank6_org buffer3 = $ org bank7_org buffer4 = $ ;************************************************************* ; Equates for the FSK receive part of the modem ;************************************************************* threshold = 180 ; How many counts to look for for a transition from high frequency to low frequency fsk_hysterises = 6 ; The number of counts over/under the threshold to allow an actual transition ; from high to low on RX-bit ;************************************************************* ;************************************************************************** ; Baud rate defines ;************************************************************************** ; *** 150 baud ; baud_bit = 7 ;for 2400 baud ; start_delay = 128+64+1 ; " " " ; int_period = 163 ; " " " ; *** 600 baud ; baud_bit = 5 ; start_delay = 32+16+1 ; int_period = 163 ; *** 1200 baud baud_bit = 4 start_delay = 16+8+1 int_period = 163 ;************************************************************************** ; Equates for common data comm frequencies ;************************************************************************** f697_h equ $012 ; DTMF Frequency f697_l equ $09d f770_h equ $014 ; DTMF Frequency f770_l equ $090 f852_h equ $016 ; DTMF Frequency f852_l equ $0c0 f941_h equ $019 ; DTMF Frequency f941_l equ $021 f1209_h equ $020 ; DTMF Frequency f1209_l equ $049 f1336_h equ $023 ; DTMF Frequency f1336_l equ $0ad f1477_h equ $027 ; DTMF Frequency f1477_l equ $071 f1633_h equ $02b ; DTMF Frequency f1633_l equ $09c ;****************************************************************************** ; Equates for FSK generation ;****************************************************************************** f390_h equ $00a ; V.23 backchannel logic '1' (mark) f390_l equ $06a f450_h equ $00c ; V.23 backchannel logic '0' (space) f450_l equ $004 f1300_h equ $022 ; V.23 forward channel logic '1' (mark) f1300_l equ $0b7 f2100_h equ $038 ; V.23 forward channel logic '0' (space) f2100_l equ $015 f2225_h equ $03b ; Bell 103 forward channel logic '1' (mark) f2225_l equ $06b f2025_h equ $036 ; Bell 103 forward channel logic '0' (space) f2025_l equ $014 f1070_h equ $01c ; Bell 103 backward channel logic '1' (mark) f1070_l equ $093 f1270_h equ $021 ; Bell 103 backward channel logic '0' (space) f1270_l equ $0ea ;********************************************************************************* ; Pin Definitions: These are the pins on the Scenix Modem board. Not all are ; necessary. Check the documentation at the top of this ; program. ;********************************************************************************* PDM_pin equ ra.0 ; D/A output pin rx_pin equ ra.1 ; RS-232 reception pin tx_pin equ ra.2 ; RS-232 transmission pin nothing equ ra.3 ; N/C RA_latch equ %11111111 ;SX18/20/28/48/52 port A latch init RA_DDIR equ %11111010 ;SX18/20/28/48/52 port A DDIR value RA_LVL equ %00000000 ;SX18/20/28/48/52 port A LVL value RA_PLP equ %11111111 ;SX18/20/28/48/52 port A PLP value led_pin equ rb.0 ; LED pin rxa_pin equ rb.1 ; FSK receive pin cntrl_1 equ rb.2 ; drive cntrl_1 low to disable the output of the LPF ring equ rb.3 ; ring detection pin hook equ rb.4 ; drive hook low to go off-hook cntrl_3 equ rb.5 ; drive cntrl_3 low to disable the output of the HPF rts equ rb.6 ; indicates to the SX that the PC wants to transmit data cts equ rb.7 ; indicates to the PC that the SX is ready to receive data RB_latch equ %11011011 ;SX18/20/28/48/52 port B latch init RB_DDIR equ %01101010 ;SX18/20/28/48/52 port B DDIR value: HPF RB_ST equ %11111111 ;SX18/20/28/48/52 port B ST value RB_LVL equ %00000000 ;SX18/20/28/48/52 port B LVL value RB_PLP equ %11111111 ;SX18/20/28/48/52 port B PLP value fskRxPort equ rb fskRxMask equ %00000010 rc_450_mask equ %11100101 ; Hybrid set-up for 450 ohms rc_600_mask equ %11010101 ; Hybrid set-up for 600 ohms rc_750_mask equ %10110101 ; Hybrid set-up for 750 ohms rc_900_mask equ %01110101 ; Hybrid set-up for 900 ohms dtmf_in_pin equ rc.0 ; DTMF input pin dtmf_fdbk_pin equ rc.1 ; Negative feedback output for DTMF input AtoD_in_pin equ rc.2 ; A/D input pin AtoD_fdbk_pin equ rc.3 ; Negative feedback for A/D input imp_450_pin equ rc.4 ; Set to an output to set hybrid for 450ohm line impedance. Tristate otherwise. imp_600_pin equ rc.5 ; Set to an output to set hybrid for 600ohm line impedance. Tristate otherwise. imp_750_pin equ rc.6 ; Set to an output to set hybrid for 750ohm line impedance. Tristate otherwise. imp_900_pin equ rc.7 ; Set to an output to set hybrid for 900ohm line impedance. Tristate otherwise. RC_latch equ %00001111 ;SX18/20/28/48/52 port C latch init RC_DDIR equ rc_600_mask ;SX18/20/28/48/52 port C DDIR value RC_ST equ %11111111 ;SX18/20/28/48/52 port C ST value RC_LVL equ %00000000 ;SX18/20/28/48/52 port C LVL value RC_PLP equ %11111111 ;SX18/20/28/48/52 port C PLP value ;********************************************************************************* ; SX18AC/20AC/28AC Mode addresses ; *On SX18/20/28, all registers addressed via mode are write only, with the exception of ; CMP and WKPND which do an exchange with W. ;********************************************************************************* ; Exchange addresses CMP equ $08 ;Exchange Comparator enable/status register with W WKPND equ $09 ;Exchange MIWU/RB Interrupts pending with W ; Port setup (read) addresses WKED_W equ $0A ;Write MIWU/RB Interrupt edge setup, 0 = falling, 1 = rising WKEN_W equ $0B ;Write MIWU/RB Interrupt edge setup, 0 = enabled, 1 = disabled ST_W equ $0C ;Write Port Schmitt Trigger setup, 0 = enabled, 1 = disabled LVL_W equ $0D ;Write Port Schmitt Trigger setup, 0 = enabled, 1 = disabled PLP_W equ $0E ;Write Port Schmitt Trigger setup, 0 = enabled, 1 = disabled DDIR_W equ $0F ;Write Port Direction ;************************ Beginning of program space *************************** org $0 ;****************************************************************************** ; Interrupt ; ; With a retiw value of -163 and an oscillator frequency of 50MHz, this ; code runs every 3.26us. ;****************************************************************************** PDM_output bank PDM_bank ; Update the PDM pin add PDM0_acc,PDM0_out snc setb PDM_pin sc clrb PDM_pin ;************************************************************************** jmp @ISR ; The ISR is in the second page, so go there. ;****************************************************************************** reset_entry ; Program Starts Here on Power Up ;****************************************************************************** ;********************************************************************** ; First, call init to initialize the program ;********************************************************************** call @init mov !option,#%00011111 ; enable wreg and rtcc interrupt setb tx_pin ; set the RS-232 tx_pin setb CTS ; Don't allow PC to transmit mov w,#25 ; delay 250 milliseconds call @delay_10n_ms ;********************************************************************** ; Send "hello" string ;********************************************************************** mov w,#_hello ; say 'hello' call @send_string mov w,#_help call @send_string ;********************************************************************** ; Send prompt ;********************************************************************** main_2 _send_prompt mov w,#_prompt ; send prompt call @send_string clrb CTS ; Allow PC to transmit clr push_index ; Clear the buffer_push pointer clr pop_index ; Clear the buffer_pop pointer ;********************************************************************** ; Fill the command buffer with input characters. Backspace will delete ; the last value entered. ;********************************************************************** _cmd_loop jnb rx_flag,$ ; Wait until we receive a byte via. RS-232 clrb rx_flag ; clear the flag bank serial mov byte,rx_byte ; Move the received byte to 'byte' and call @uppercase ; convert it to uppercase mov w,#$20 ; compare the byte to ' ' xor w,byte jz _cmd_loop ; If byte == space, ignore it. mov w,#$0a ; compare the byte to LF xor w,byte jz _cmd_loop ; If byte == line feed, ignore it. mov w,#$0d ; compare the byte to CR xor w,byte jz :enter ; if byte == CR, parse the string. mov w,byte ; if it does not resemble the above characters, echo it. call @send_byte ; send via. RS-232 mov w,#$08 ; compare the byte to a backspace. xor w,byte jz :backspace ; if it equals a backspace, delete one character in the buffer. call @buffer_push ; otherwise, store it jmp _cmd_loop ; and come back for more. :backspace call @buffer_backspace jmp _cmd_loop :enter ; If the user presses enter, then parse the string. ;************************************************************************** ; String parser (Checks to see if buffer = any commands) ; -Checks contents of ascii buffer against any commands stored in ROM ; -If a command = the contents of the ascii buffer, a routine will be called ; -Each routine MUST perform a retw 0 on exit, or parse_string will not ; know that a routine has run and it should exit back to command mode. ; -Exits back to command mode when it detects a zero after the table look-up. ; -Outputs 'OK' if no commands are matched. ;************************************************************************** parse_string clr pop_index ; Clear the index into the ascii buffer clr command_index ; And the index into the commands :loop call @buffer_get ; Get a vale from the buffer at ascii_index call command_table ; Get a character from one of the commands test wreg ; If the return value is 0, then this matched jz :nothing ; the command and ran a routine. Exit. bank serial xor w,byte ; compare the command's character with the jnz :not_equal ; buffer's character. call @inc_pop_index ; Increment the index into the buffer. jmp :loop :not_equal inc command_index ; If the buffer did not equal the command, clr pop_index ; start from the beginning of a new command cjne command_index,#5,:loop ; compare command_index with 5 (This number = # of commands) :nothing clrb fsk_rx_en setb tx_pin mov w,#20 call @delay_10n_ms mov w,#_CR call @send_string mov w,#_OK ; If we have checked all 5 commands, then this call @send_string ; did not equal any so send an 'OK' message. :done bank buffer clr pop_index clr push_index clr buffer jmp _send_prompt ;************************************************************************** command_table mov w,command_index add pc,w tableStart ; Will cause a compiler error if not located in the lower half of a page. jmp command_1 jmp command_2 jmp command_3 jmp command_4 jmp command_5 tableEnd ; Will cause a compiler error if not located in the lower half of a page. ;************************************************************************** command_1 ; Dial command mov w,pop_index add PC,w tableStart ; Will cause a compiler error if not located in the lower half of a page. retw 'A' retw 'T' retw 'D' retw 'T' jmp DIAL_MODE tableEnd ; Will cause a compiler error if not located in the lower half of a page. ;************************************************************************** command_2 ; Hang up command mov w,pop_index add PC,w tableStart ; Will cause a compiler error if not located in the lower half of a page. retw 'A' retw 'T' retw 'H' jmp HANG_UP tableEnd ; Will cause a compiler error if not located in the lower half of a page. ;************************************************************************** command_3 ; Initialize mov w,pop_index add PC,w tableStart ; Will cause a compiler error if not located in the lower half of a page. retw 'A' retw 'T' retw 'Z' jmp INITIALIZE tableEnd ; Will cause a compiler error if not located in the lower half of a page. ;************************************************************************** command_4 ; Data mode mov w,pop_index add PC,w tableStart ; Will cause a compiler error if not located in the lower half of a page. retw 'A' retw 'T' retw 'O' jmp FSK_IO tableEnd ; Will cause a compiler error if not located in the lower half of a page. ;************************************************************************** command_5 ; Hybrid Set-up mov w,pop_index add PC,w tableStart ; Will cause a compiler error if not located in the lower half of a page. retw '?' jmp HELP tableEnd ; Will cause a compiler error if not located in the lower half of a page. ;************************************************************************** ; END of String parser (Checks to see if buffer = any commands) ;************************************************************************** ;********************************************************************** ; Hang Up ;********************************************************************** HANG_UP call @disable_o clrb fsk_rx_en ; Disable fsk detection mov w,#50 call @delay_100n_ms ; Pause for 5 seconds. setb hook ; hang-up retw 0 ;********************************************************************** ; Initialize ;********************************************************************** INITIALIZE mov w,#10 call @delay_100n_ms ; Pause for 1 second call @init clr flags retw 0 ;********************************************************************** ; Send Help string ;********************************************************************** HELP mov w,#_HELP call @send_string retw 0 ;************************************************************************** ; Dial Mode: ; -Dials contents of ascii buffer, starting from location pointed ; to by ascii_index. ; -Responds to these commands: ; 0-9, *, # - Dials the specified number ; , - Pause for 2 seconds ; -Jumps to data mode after dialing. ;************************************************************************** DIAL_MODE clrb sine_gen_en ; Disable sine generation clrb fsk_tx_en ; Disable fsk generation clrb dtmf_gen_en ; Disable dtmf generation clrb hook ; go off-hook mov m,#$0f mov w,#%01101010 ; rb.5 (cntrl_3) is tristate, rb.2 (cntrl_1) is low mov !rb,w clrb cntrl_1 ; Enable lowest low-pass filter on output mov w,#40 ; delay 4 seconds before dialing call @delay_100n_ms mov w,#_CR ; Send a carriage return call @send_string mov w,#_DIALING ; send "Dialing" to screen call @send_string bank serial :dial_loop call @buffer_get ; Get a character from the buffer call @uppercase ; convert it to uppercase mov w,byte ; test byte for zero snz jmp :originate_mode ; If byte is zero, dialing is done. call @send_byte cje byte,#',',:pause ; if the character = ',', pause for 2s call @digit_2_index ; convert the ascii digit to an ; index value call @load_frequencies ; load the frequency registers call @dial_it ; dial the number for 60ms and return. :inc call @inc_pop_index ; increment the index into the table jmp :dial_loop :pause mov w,#20 ; delay 2s call @delay_100n_ms jmp :inc :originate_mode ;****************************************************************** ; Set/clear proper flags for origination ;****************************************************************** bank fsk_transmit_bank clr fsk_tx_divide_2 ; clear the transmit-divider clr flags ; clear all flags. clrb fsk_answering ; we are not answering. setb fsk_tx_bit ; set the transmit bit to logic '1' setb sine_gen_en ; enable the sine generators setb fsk_tx_en ; enable the fsk transmitter mov w,#50 ; delay 5 seconds after dialing to wait for carrier call @delay_100n_ms jb carrier_detected,FSK_IO ; if there still is no carrier, exit mov w,#50 ; delay 5 seconds after dialing to wait for carrier call @delay_100n_ms jb carrier_detected,FSK_IO ; if there still is no carrier, exit mov w,#100 ; delay 10 seconds after dialing to wait for carrier call @delay_100n_ms jb carrier_detected,FSK_IO mov w,#150 ; delay 15 seconds after dialing to wait for carrier call @delay_100n_ms jb carrier_detected,FSK_IO no_carrier clrb fsk_rx_en setb tx_pin mov w,#80 ; give carrier 8 more seconds to re-appear call @delay_100n_ms jb carrier_detected,FSK_IO_AGAIN mov w,#_no_carrier call @send_string jmp INITIALIZE ;****************************************************************** ; Once at FSK I/O mode, the program sends/receives data. In ; originate mode, the send is at 75bps and the receive is at 1200bps. ; Because of the difference in baud rates, hardware flow control ; is used. CTS is disabled when the buffer is close to capacity, ; and re-enabled when the buffer is completely empty. ;****************************************************************** FSK_IO mov w,#_DATA_MODE ; Send "connect" message call @send_string FSK_IO_AGAIN clr plus_count ; clear the plus count clr push_index ; clear the push pointer to buffer clr pop_index ; clear the pop pointer to buffer setb fsk_rx_en ; enable the FSK reception part of ISR mov m,#$0f mov w,#%01101010 ; rb.5 (cntrl_3) is tristate, rb.2 (cntrl_1) is low mov !rb,w clrb cntrl_1 ; Enable lowest low-pass filter on output clrb cts ; clear CTS to tell PC "ready for data" ;****************************************************************** ; This is the main loop for FSK I/O. Sends FSK bytes, and receives ; bytes from the UART. The FSK receive portion of FSK I/O is completely ; handled by the ISR ;****************************************************************** :loop2 jnb timer_flag,:no_timeout ; if (timer_flag) bank serial test plus_count ; if (plus_count) jz :no_timeout mov w,plus_count ; if (plus_count==3) xor w,#3 ; return; snz retw 0 jmp :clr_plus_count ; else clr_plus_count(); ; else no_timout(); ; else no_timeout(); :no_timeout jnb carrier_detected,no_carrier jb rx_flag,:got_byte ; Received a byte of data. Handle it. bank fsk_transmit_bank ; If no byte, check to see if we need to transmit test fsk_tx_count ; Are we transmitting anything? sz ; if no, then send next byte. jmp :loop2 ; else jump here forever (ISR does all the work) mov w,pop_index ; If pop_index == push_index, everything in the buffer has been sent. xor w,push_index sz jmp :not_empty_yet ;****************************************************************** ; The buffer is empty: initialize the buffer and enable CTS. ;****************************************************************** :empty clr push_index ; so clear the buffer indexes clr pop_index clrb cts ; and clear cts to allow more data from DCE jmp :loop2 ;****************************************************************** ; The buffer is not empty, keep sending stuff.. ;****************************************************************** :not_empty_yet call @buffer_get ; if the buffer is not empty, get the next byte call @fsk_send_byte ; from the buffer and send it via. FSK call @inc_pop_index ; and increment the pop index and pop_index,#$0f jmp :loop2 ;****************************************************************** ; The we just received a byte, so put it on the buffer. ;****************************************************************** :got_byte bank serial clrb rx_flag mov byte,rx_byte call @buffer_push ;****************************************************************** ; Check to see if the pop index is at (push index + 5) ;****************************************************************** and push_index,#$0f mov w,#5 add w,push_index and w,#$0f ; keep push index < 16 xor w,pop_index ; if (push_index + 5 == pop_index, the buffer is almost full so indicate this) snz setb cts ; If push index == pop index, disable CTS bank serial mov w,#'+' ; If the byte = '+', increment plus_count, otherwise, plus_count == 0 xor w,rx_byte ; If byte = '+' jz :plus_received ; plus_received(); :clr_plus_count ; Else clr plus_count ; clr_plus_count(); mov w,#255 ; call @reset_timers ; jmp :loop2 ; :plus_received ; plus_received(); test plus_count ; If !(plus_count) jz :zero_plus_count ; zero_plus_count(); :some_pluses jb timer_flag,:clr_plus_count; else if (timer_flag) :inc_plus_count inc plus_count ; clr_plus_count(); mov w,#200 ; else call @reset_timers ; inc_plus_count(); jmp :loop2 :zero_plus_count sb timer_flag ; If (timer_flag) jmp :clr_plus_count ; clr_plus_count(); jmp :inc_plus_count ; else inc_plus_count ;************************************************************************** ; Miscellaneous subroutines.... ;************************************************************************** org $200 ;************************************************************************** reset_timers ; This subroutine times 'w' ticks, and returns with a '1' in w when ; the specified time has timed out. Each tick is 13.35296 ms. ; This subroutine uses the TEMP2 register. Call this routine with w = 0 ; to poll for a time_out. ;************************************************************************** bank timers not w inc wreg mov timer_h,w clr timer_l clrb timer_flag retp ;************************************************************************** buffer_push ; This subroutine pushes the contents of byte onto the 64-byte ascii buffer. ;************************************************************************** bank serial ; Move the byte into the buffer mov temp,byte mov fsr,#buffer add fsr,push_index mov indf,temp ; Increment index and keep it in range call @inc_push_index mov fsr,#buffer ; Null terminate the buffer. add fsr,push_index clr indf bank serial retp ;************************************************************************** ;************************************************************************** buffer_backspace ; This subroutine deletes one value of the buffer and decrements the index ;************************************************************************** dec push_index and push_index,#%01101111 mov fsr,#buffer add fsr,push_index clr indf bank serial retp ;************************************************************************** inc_pop_index ;************************************************************************** mov fsr,#pop_index jmp inc_index ;************************************************************************** inc_push_index ;************************************************************************** mov fsr,#push_index ;************************************************************************** inc_index ; This subroutine increments the index into the buffer ;************************************************************************** mov w,indf and w,#%00001111 xor w,#%00001111 jnz :not_on_verge inc indf mov w,#16 add w,indf and w,#$7f mov indf,w retp :not_on_verge inc indf retp ;************************************************************************** buffer_get ; This subroutine retrieves the buffered value at index ;************************************************************************** mov fsr,#buffer add fsr,pop_index mov w,indf bank serial mov byte,w retp ;************************************************************************** delay_10n_ms ; This subroutine delays 'w'*10 milliseconds. (not exactly, but pretty close) ; This subroutine uses the TEMP register ; INPUT w - w/10 milliseconds to delay for. ; OUTPUT Returns after 10 * n milliseconds. ;************************************************************************** mov temp,w bank timers :loop clrb timer_flag ; This loop delays for 10ms mov timer_h,#$0ff mov timer_l,#$041 jnb timer_flag,$ dec temp ; do it w-1 times. jnz :loop clrb timer_flag retp ;************************************************************************** delay_100n_ms ; This subroutine delays 'w'*100 milliseconds. (not exactly, but pretty close) ; This subroutine uses the TEMP register ; INPUT w - w/100 milliseconds to delay for. ; OUTPUT Returns after 100 * n milliseconds. ;************************************************************************** mov temp,w bank timers :loop clrb timer_flag ; This loop delays for 10ms mov timer_h,#$0f8 mov timer_l,#$083 jnb timer_flag,$ dec temp ; do it w-1 times. jnz :loop clrb timer_flag retp ;************************************************************************** zero_ram ; Subroutine - Zero all ram. ; INPUTS: None ; OUTPUTS: All ram locations (except special function registers) are = 0 ;************************************************************************** CLR FSR :loop SB FSR.4 ;are we on low half of bank? SETB FSR.3 ;If so, don't touch regs 0-7 CLR IND ;clear using indirect addressing IJNZ FSR,:loop ;repeat until done retp ;************************************************************************** ; Subroutine - Disable the outputs ; Load DC value into PDM and disable the output switch. ;************************************************************************** disable_o bank PDM_bank ; input mode. mov PDM0_out,#128 ; put 2.5V DC on PDM output pin clrb sine_gen_en clrb dtmf_gen_en clrb fsk_tx_en retp ;************************************************************************** init ; Initializes the program. ;************************************************************************** _mode ST_W ;point MODE to write ST register mov w,#RB_ST ;Setup RB Schmitt Trigger, 0 = enabled, 1 = disabled mov !rb,w mov w,#RC_ST ;Setup RC Schmitt Trigger, 0 = enabled, 1 = disabled mov !rc,w _mode LVL_W ;point MODE to write LVL register mov w,#RA_LVL ;Setup RA CMOS or TTL levels, 0 = TTL, 1 = CMOS mov !ra,w mov w,#RB_LVL ;Setup RB CMOS or TTL levels, 0 = TTL, 1 = CMOS mov !rb,w mov w,#RC_LVL ;Setup RC CMOS or TTL levels, 0 = TTL, 1 = CMOS mov !rc,w _mode PLP_W ;point MODE to write PLP register mov w,#RA_PLP ;Setup RA Weak Pull-up, 0 = enabled, 1 = disabled mov !ra,w mov w,#RB_PLP ;Setup RB Weak Pull-up, 0 = enabled, 1 = disabled mov !rb,w mov w,#RC_PLP ;Setup RC Weak Pull-up, 0 = enabled, 1 = disabled mov !rc,w _mode DDIR_W ;point MODE to write DDIR register mov w,#RA_DDIR ;Setup RA Direction register, 0 = output, 1 = input mov !ra,w mov w,#RB_DDIR ;Setup RB Direction register, 0 = output, 1 = input mov !rb,w mov w,#RC_DDIR ;Setup RC Direction register, 0 = output, 1 = input mov !rc,w mov w,#RA_latch ;Initialize RA data latch mov ra,w mov w,#RB_latch ;Initialize RB data latch mov rb,w mov w,#RC_latch ;Initialize RC data latch mov rc,w setb hook ; go on hook. clrb cts setb led_pin ; turn on LED clr flags ; Clear all flags call zero_ram call @disable_o retp ;************************************************************************** ; Subroutine - Get byte via serial port and echo it back to the serial port ; INPUTS: ; -NONE ; OUTPUTS: ; -received byte in rx_byte ;************************************************************************** get_byte jnb rx_flag,$ ;wait till byte is received clrb rx_flag ;reset the receive flag bank serial ;switch to serial bank mov byte,rx_byte ;store byte (copy using W) ; & fall through to echo char back ;************************************************************************** ; Subroutine - Send byte via serial port ; INPUTS: ; w - The byte to be sent via RS-232 ;************************************************************************** send_byte bank serial :wait test tx_count ;wait for not busy jnz :wait ; not w ;ready bits (inverse logic) mov tx_high,w ; store data byte setb tx_low.7 ; set up start bit mov tx_count,#10 ;1 start + 8 data + 1 stop bit RETP ;leave and fix page bits ;************************************************************************** ; Subroutine - Send byte via serial port ; INPUTS: ; w - The byte to be sent via RS-232 ;************************************************************************** fsk_send_byte bank fsk_serial_bank :wait test fsk_tx_count ;wait for not busy jnz :wait ; not w ;ready bits (inverse logic) mov fsk_tx_high,w ; store data byte setb fsk_tx_low.7 ; set up start bit mov fsk_tx_count,#10 ;1 start + 8 data + 1 stop bit RETP ;leave and fix page bits ;************************************************************************** ; Subroutine - Send string pointed to by address in W register ; INPUTS: ; w - The address of a null-terminated string in program ; memory ; OUTPUTS: ; outputs the string via. RS-232 ;************************************************************************** send_string bank serial mov string,w ;store string address :loop mov w,string ;read next string character mov m,#3 ; with indirect addressing iread ; using the mode register mov m,#$F ;reset the mode register test w ;are we at the last char? snz ;if not=0, skip ahead RETP ;yes, leave & fix page bits call send_byte ;not 0, so send character inc string ;point to next character jmp :loop ;loop until done ;************************************************************************** ; Subroutine - Make byte uppercase ; INPUTS: ; byte - The byte to be converted ; OUTPUTS: ; byte - The uppercase byte ;************************************************************************** uppercase csae byte,#'a' ;if byte is lowercase, then skip ahead RETP sub byte,#'a'-'A' ;change byte to uppercase RETP ;leave and fix page bits ;************************************************************************** org $300 ;************************************************************************** ; String data (for RS-232 output) and tables ;************************************************************************** _hello dw 13,10,'V.23 Originate V.1.37',13,10,0 _instructions dw '- ? For Help',0 _DIALING dw 'DIAL ',0 _PROMPT dw 13,10,'>',0 _OK dw 'OK',13,10,0 _CR dw 13,10,0 _DATA_MODE dw 13,10,'CONNECT 1275',13,10,0 _no_carrier dw 13,10,'NO CARRIER',0 _HELP dw 13,10,'ATDT- Dial',13,10,'ATH - Hang Up',13,10,'ATO - Data Mode',13,10,'ATZ - Init',13,10,'+++ - Command Mode',0 ;************************************************************************** org $400 ; FSK subroutines and the Interrupt Service Routine. ;************************************************************************** answer_tone ; This subroutine sends out an answer tone of 2100Hz for 3 seconds. ;************************************************************************** bank sine_gen_bank ; send out the answer tone for 3 seconds clr curr_sine mov freq_count_high2,#f2100_h mov freq_count_low2,#f2100_l setb sine_gen_en ; enable the FSK transmitter mov w,#30 call @delay_100n_ms retp ;************************************************************************** ; THESE ROUTINES ARE RUN WITHIN THE ISR... DO NOT CALL THEM FROM THE MAINLINE. ;************************************************************************** ;****************************************************************************** carrier_detect bank carrier_detect_bank inc cd_trans_count jnz :no_rollover dec cd_trans_count jmp :sample :no_rollover mov w,rb xor w,cd_rb_past_state and w,#%00000010 snz retp xor cd_rb_past_state,w sb cd_rb_past_state.1 retp :sample mov w,cd_trans_count add cd_trans_avg_l,w snc inc cd_trans_avg_h clr cd_trans_count inc cd_avg_count sz retp setb carrier_detected mov w,#-8 add w,cd_trans_avg_h sc clrb carrier_detected mov w,#-16 add w,cd_trans_avg_h snc clrb carrier_detected clr cd_trans_avg_h clr cd_trans_avg_l retp ;************************************************************************** fsk_receive_main ; This code is speed critical and runs in every ; ISR. It increments the FSK transition couters ; and checks for a transition. If a transition ; has occured, it sets a flag, and saves the ; transition count for later processing by the ; fsk_receive_processing1 subroutine. ;************************************************************************** bank fsk_receive_bank sb fsk_rx_en retp inc fsk_trans_count snz dec fsk_trans_count mov w,fsk_rb_past_state xor w,rb and w,#%00000010 snz retp xor fsk_rb_past_state,w setb fsk_processing_required_1 mov fsk_temp_trans,fsk_trans_count clr fsk_trans_count retp ;************************************************************************** fsk_receive_main_2 ; This code removes some of the jitter away from ; the low frequency detection algorithm by ; continuously checking the transition count ; to see if it has now reached a point where it ; is safe to say that there is no high frequency ; present. ;************************************************************************** bank fsk_receive_bank sb fsk_rx_en retp mov w,#-(threshold+fsk_hysterises) add w,fsk_trans_count snc ; setb fsk_rx_bit ; setb test_pin setb tx_pin add w,fsk_last_trans snc ; setb test_pin ; setb fsk_rx_bit setb tx_pin retp ;************************************************************************** fsk_receive_processing1 ; This subroutine runs only when a transition has ; occurred. It adds the last transition count ; to the current one and checks this against the ; high/low frequency threshold. If the transition ; count is below the threshold, the fsk_rx_bit ; flag is cleared. ;************************************************************************** bank fsk_receive_bank sb fsk_processing_required_1 retp ; Exit if disabled clrb fsk_processing_required_1 mov w,#-25 ; compare the transition count with 5 add w,fsk_temp_trans jnc :glitch ; If the transition count is less than 5, handle the glitch. mov w,#-(threshold-fsk_hysterises) ; compare the transition count with add w,fsk_temp_trans ; the threshold (-hysterises) snc mov w,#$ff add w,fsk_last_trans sc ; clrb test_pin ; clrb fsk_rx_bit clrb tx_pin ; Clear the TX_PIN if the transition count is less than the threshold mov fsk_last_trans,fsk_temp_trans ; save the last transition count. retp :glitch mov w,fsk_last_trans ; of the last transition add w,fsk_temp_trans snc mov w,#$ff mov fsk_last_trans,w retp ;************************************************************************** task_manager ; This portion of the ISR allows 1 of 16 separate tasks to run in each ; interrupt. ;************************************************************************** inc task_switcher mov w,task_switcher and w,#$0f jmp pc+w tableStart ; Will cause a compiler error if not located in the lower half of a page. ;*** TASKS *** jmp fsk_receive_main_2 ;0 jmp transmit ;1 jmp receive ;2 jmp fsk_transmit_uart ;3 jmp fsk_receive_main_2 ;4 jmp transmit_fsk ;5 jmp do_timers ;6 jmp fsk_receive_processing1 ;7 jmp fsk_receive_main_2 ;8 jmp carrier_detect ;9 retp ;10 retp ;11 jmp fsk_receive_main_2 ;12 retp ;13 retp ;14 retp ;15 jmp fsk_receive_main_2 ;16 retp ; (just in case) tableEnd ; Will cause a compiler error if not located in the lower half of a page. ;************************************************************************** fsk_transmit_uart ; This is an asynchronous RS-232 transmitter ; INPUTS: ; tx_divide.baud_bit - Transmitter only executes when this bit is = 1 ; tx_high - Part of the data to be transmitted ; tx_low - Some more of the data to be transmitted ; tx_count - Counter which counts the number of bits transmitted. ; OUTPUTS: ; tx_pin - Sets/Clears this pin to accomplish the transmission. ;************************************************************************** bank fsk_serial_bank sb fsk_answering inc fsk_tx_divide_2 and fsk_tx_divide_2,#$0f ; Divide the 1200bps UART by 16 to ; achieve 75bps sz retp clrb fsk_tx_divide.baud_bit ;clear xmit timing count flag inc fsk_tx_divide ;only execute the transmit routine STZ ;set zero flag for test SNB fsk_tx_divide.baud_bit ; every 2^baud_bit interrupt test fsk_tx_count ;are we sending? snz retp ;if not, go to :receive clc ;yes, ready stop bit rr fsk_tx_high ; and shift to next bit rr fsk_tx_low ; dec fsk_tx_count ;decrement bit counter movb fsk_tx_bit,/fsk_tx_low.6 ;output next bit retp ;************************************************************************** transmit ; This is an asynchronous RS-232 transmitter ; INPUTS: ; tx_divide.baud_bit - Transmitter only executes when this bit is = 1 ; tx_high - Part of the data to be transmitted ; tx_low - Some more of the data to be transmitted ; tx_count - Counter which counts the number of bits transmitted. ; OUTPUTS: ; tx_pin - Sets/Clears this pin to accomplish the transmission. ;************************************************************************** bank serial clrb tx_divide.baud_bit ;clear xmit timing count flag inc tx_divide ;only execute the transmit routine STZ ;set zero flag for test SNB tx_divide.baud_bit ; every 2^baud_bit interrupt test tx_count ;are we sending? snz retp ;if not, go to :receive clc ;yes, ready stop bit rr tx_high ; and shift to next bit rr tx_low ; dec tx_count ;decrement bit counter movb tx_pin,/tx_low.6 ;output next bit retp ;************************************************************************** receive ; This is an asynchronous receiver for RS-232 reception ; INPUTS: ; rx_pin - Pin which RS-232 is received on. ; OUTPUTS: ; rx_byte - The byte received ; rx_flag - Set when a byte is received. ;************************************************************************** bank serial movb c,rx_pin ;get current rx bit test rx_count ;currently receiving byte? jnz :rxbit ;if so, jump ahead mov w,#9 ;in case start, ready 9 bits sc ;skip ahead if not start bit mov rx_count,w ;it is, so renew bit count mov rx_divide,#start_delay ;ready 1.5 bit periods :rxbit djnz rx_divide,:rxdone ;middle of next bit? setb rx_divide.baud_bit ;yes, ready 1 bit period dec rx_count ;last bit? sz ;if not rr rx_byte ; then save bit snz ;if so setb rx_flag ; then set flag :rxdone retp ;************************************************************************** do_timers ; The 24-bit timer increments every 52.16us when called by task_manager. ;************************************************************************** bank timers ; Update the timers inc timer_l snz inc timer_h snz setb timer_flag snz inc timer_hh snz dec timer_hh setb led_pin sb timer_h.2 clrb led_pin retp ;************************************************************************** transmit_fsk ;************************************************************************** bank fsk_transmit_bank sb fsk_tx_en retp jb fsk_answering,transmit_answer_tones transmit_originate_tones jnb fsk_tx_bit,:low_bit :high_bit bank sine_gen_bank mov freq_count_high2,#f390_h mov freq_count_low2,#f390_l retp :low_bit bank sine_gen_bank mov freq_count_high2,#f450_h mov freq_count_low2,#f450_l retp transmit_answer_tones jnb fsk_tx_bit,:low_bit :high_bit bank sine_gen_bank mov freq_count_high2,#f1300_h mov freq_count_low2,#f1300_l retp :low_bit bank sine_gen_bank mov freq_count_high2,#f2100_h mov freq_count_low2,#f2100_l retp ;****************************************************************************** ; Interrupt ; ; With a retiw value of -163 and an oscillator frequency of 50MHz, this ; code runs every 3.26us. ;****************************************************************************** ISR ;****************************************************************************** FSK_output jnb dtmf_gen_en,:dtmf_disabled call @sine_generator1 call @DTMF_twist jmp :task_switcher :dtmf_disabled jnb sine_gen_en,:task_switcher ; Output the frequencies set by the freq_count registers call @sine_generator2 call @SINE_out ; Output each discrete value of the sine table call fsk_receive_main :task_switcher call task_manager ;****************************************************************************** ISR_DONE ; This is the end of the interrupt service routine. Now load -163 into w and ; perform a retiw to interrupt 163 cycles from the start of this one. ; (3.26us@50MHz) ;****************************************************************************** mov w,#-163 ;1 ; interrupt 163 cycles after this interrupt retiw ;3 ; return from the interrupt ;****************************************************************************** ; End of the Interrupt Service Routine ;****************************************************************************** ;************************************************************************** org $600 ; These subroutines are on page 3. ;************************************************************************** ; DTMF transmit functions/subroutines ;************************************************************************** ;************************************************************************** DTMF_TABLE ; DTMF tone constants ; This routine returns with the constant used for each of the frequency ; detectors. ; INPUT: w - Index into the table (0-15 value) ; OUTPUT: w - Constant at that index ;************************************************************************** jmp PC+w tableStart ; Will cause a compiler error if not located in the lower half of a page. retw f697_l retw f697_h retw f770_l retw f770_h retw f852_l retw f852_h retw f941_l retw f941_h retw f1209_l retw f1209_h retw f1336_l retw f1336_h retw f1477_l retw f1477_h retw f1633_l retw f1633_h tableEnd ; Will cause a compiler error if not located in the lower half of a page. ;************************************************************************** ASCII_TABLE ; Ascii value at index (0-15) ; INPUT: w - Index into the table (0-15 value) ; OUTPUT: w - Constant at that index ;************************************************************************** jmp PC+w tableStart ; Will cause a compiler error if not located in the lower half of a page. retw '1' retw '2' retw '3' retw 'A' retw '4' retw '5' retw '6' retw 'B' retw '7' retw '8' retw '9' retw 'C' retw '*' retw '0' retw '#' retw 'D' tableEnd ; Will cause a compiler error if not located in the lower half of a page. ;************************************************************************** index_2_digit ; This subroutine converts a digit from 0-9 or a '*' or a '#' to a table ; lookup index which can be used by the load_frequencies subroutine. To use ; this routine, pass it a value in the 'byte' register. No invalid digits ; are used. (A, B, C, or D) ;************************************************************************** call ASCII_TABLE retp ;************************************************************************** digit_2_index ; This subroutine converts a digit from 0-9 or a '*' or a '#' to a table ; lookup index which can be used by the load_frequencies subroutine. To use ; this routine, pass it a value in the 'byte' register. No invalid digits ; are used. (A, B, C, or D) ;************************************************************************** bank serial clr temp :loop mov w,temp call ASCII_TABLE xor w,byte jz :done inc temp jb temp.4,:done jmp :loop :done mov w,temp retp ;************************************************************************** load_frequencies ; This subroutine loads the frequencies using a table lookup approach. ; The index into the table is passed in the byte register. The DTMF table ; must be in the range of $400 to $500. ;************************************************************************** mov temp,w bank sine_gen_bank mov w,>>temp and w,#%00000110 call DTMF_TABLE mov freq_count_low,w mov w,>>temp and w,#%00000110 inc wreg call DTMF_TABLE mov freq_count_high,w rl temp setb temp.3 mov w,temp and w,#%00001110 mov temp,w call DTMF_TABLE mov freq_count_low2,w mov w,temp inc wreg call DTMF_TABLE mov freq_count_high2,w retp ;************************************************************************** dial_it ; This subroutine puts out whatever frequencies were loaded ; for 100ms, and then stops outputting the frequencies. ;************************************************************************** bank sine_gen_bank clr sine_index clr sine_index2 mov w,#1 call @delay_100n_ms ; delay 100ms setb dtmf_gen_en mov w,#1 call @delay_100n_ms ; delay 100ms clrb dtmf_gen_en call @disable_o ; now disable the outputs :end_dial_it retp ;************************************************************************** sine_generator1 ;(Part of interrupt service routine) ; This routine generates a sine wave with values from the sine table ; at the end of this program. Frequency is specified by the counter. To set ; the frequency, put this value into the 16-bit freq_count register: ; freq_count = FREQUENCY * 6.83671552 (@50MHz) ;************************************************************************** bank sine_gen_bank clrb swCarryFlag add freq_acc_low,freq_count_low snc setb swCarryFlag add freq_acc_high,freq_count_high snb swCarryFlag inc freq_acc_high snz jmp :change ; if zero, this definetely caused a rollover. sc jmp :no_change :change inc sine_index mov w,sine_index and w,#$1f call sine_table mov curr_sine,w ;1 :no_change ;************************************************************************** sine_generator2 ;(Part of interrupt service routine) ; This routine generates a sine wave with values from the sine table ; at the end of this program. Frequency is specified by the counter. To set ; the frequency, put this value into the 16-bit freq_count register: ; freq_count = FREQUENCY * 6.83671552 (@50MHz) ;************************************************************************** bank sine_gen_bank clrb swCarryFlag add freq_acc_low2,freq_count_low2 snc setb swCarryFlag add freq_acc_high2,freq_count_high2 snb swCarryFlag inc freq_acc_high2 snz jmp :change ; if zero, this definetely caused a rollover. sc jmp :no_change :change inc sine_index2 mov w,sine_index2 and w,#$1f call sine_table mov curr_sine2,w :no_change retp ;************************************************************************** SINE_out ; This subroutine moves the FSK output to the PDM register ;************************************************************************** bank sine_gen_bank mov w,#127 add w,curr_sine2 mov PDM0_out,w retp ;************************************************************************** DTMF_twist ; This subroutine adds twist to the high frequency of the DTMF output. ;************************************************************************** bank sine_gen_bank mov PDM0_out,curr_sine2 ; mov sin2 into PDM0 rr wreg rr wreg and w,#$3f snb wreg.5 or w,#$C0 add PDM0_out,w ; (1.25)(sin2) = sin2 + (0.25)(sin2) add PDM0_out,curr_sine ; add the value of SIN into the PDM output add PDM0_out,#128 ; for result = PDM0 = 1.25*sin2 + 1*sin retp ; return with page bits intact ;****************************************************************************** sine_table ; The values in this table can be changed to increase/decrease the amplitude of ; the output sine wave. ; This sine table gives an output level of approximately -15dB into a 600 ohm ; impedance ;****************************************************************************** jmp pc+w tableStart ; Will cause a compiler error if not located in the lower half of a page. retw 0 retw 4 retw 8 retw 11 retw 14 retw 16 retw 18 retw 19 retw 20 retw 19 retw 18 retw 16 retw 14 retw 11 retw 8 retw 4 retw 0 retw -4 retw -8 retw -11 retw -14 retw -16 retw -18 retw -19 retw -20 retw -19 retw -18 retw -16 retw -14 retw -11 retw -8 retw -4 tableEnd ; Will cause a compiler error if not located in the lower half of a page. ; Will cause a compiler error if not locat ;****************************************************************************** ; Copyright © 1998 Scenix Semiconductor, Inc. All rights ; reserved. ; ; Scenix Semiconductor, Inc. assumes no responsibility or liability for ; the use of this [product, application, software, any of these products]. ; ; Scenix Semiconductor conveys no license, implicitly or otherwise, under ; any intellectual property rights. ; Information contained in this publication regarding (e.g.: application, ; implementation) and the like is intended through suggestion only and may ; be superseded by updates. Scenix Semiconductor makes no representation ; or warranties with respect to the accuracy or use of these information, ; or infringement of patents arising from such use or otherwise. ; ; Scenix Semiconductor products are not authorized for use in life support ; systems or under conditions where failure of the product would endanger ; the life or safety of the user, except when prior written approval is ; obtained from Scenix Semiconductor. ;******************************************************************************
| file: /Techref/scenix/lib/io/dev/modem/v_23_originate_1_37.src, 68KB, , updated: 2001/10/27 13:18, local time: 2024/4/18 15:31,
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