; RS232<->MIDI Gateway for use with Host Port software and/or YAMAHA CBX driver ; Hardware/Software : Benoît BOUCHEZ for ELEKTOR ; Version 1.00 : 10/1999 ; Version 1.10 : 05/2000 : - New buffering system for MIDI->RS ; - P1.6 pushbutton to clear overflow LED ; - MIDI RESET message on RS232 clears overflow LED ; - Simplified RTS/CTS handling (CTS set to 1) ; - T2 = test output for MIDI Clock 0000 CPU "C:\WINC32\8051.TBL" ; Use 8051 assembly model 0000 HOF "INT8" ; Output format is Intel HEX 0000 INCL "INC80320.ASM" ; Add 80C320 specific registers ; Table des bits et registres du DALLAS 80C320 ; Registres 00F0 = B: EQU 0F0H ;B REGISTER 00E0 = ACC: EQU 0E0H ;ACCUMULATOR 00D0 = PSW: EQU 0D0H ;PROGRAM STATUS WORD 00B8 = IPC: EQU 0B8H ;INTERRUPT PRIORITY 00B0 = P3: EQU 0B0H ;PORT 3 00A8 = IEC: EQU 0A8H ;INTERRUPT ENABLE 00A0 = P2: EQU 0A0H ;PORT 2 0099 = SBUF0: EQU $99 ; Serial Buffer Port 0 0098 = SCON0: EQU $98 ; Serial Control Port 0 0090 = P1: EQU 90H ;PORT 1 008D = TH1: EQU 8DH ;TIMER 1 HIGH 008C = TH0: EQU 8CH ;TIMER 0 HIGH 008B = TL1: EQU 8BH ;TIMER 1 LOW 008A = TL0: EQU 8AH ;TIMER 0 LOW 0089 = TMOD: EQU 89H ;TIMER MODE 0088 = TCON: EQU 88H ;TIMER CONTROL 0087 = PCON: EQU 87H ;POWER CONTROL REGISTER 0083 = DPH: EQU 83H ;DATA POINTER HIGH 0082 = DPL: EQU 82H ;DATA POINTER LOW 0081 = SP: EQU 81H ;STACK POINTER 0080 = P0: EQU 80H ;PORT 0 00C0 = SCON1: EQU $C0 ; Serial Control Port 1 00C1 = SBUF1: EQU $C1 ; Serial Buffer Port 1 00C8 = T2CON: EQU $C8 ; Timer 2 Control 00C9 = T2MOD: EQU $C9 ; Timer 2 Mode 00CA = RCAP2L: EQU $CA ; Timer 2 Capture Low 00CB = RCAP2H: EQU $CB ; Timer 2 Capture High 00CC = TL2: EQU $CC ; Timer 2 Low 00CD = TH2: EQU $CD ; Timer 2 High ;Bits 00D7 = CY: EQU 0D7H ;CARRY FLAG 00D6 = AC: EQU 0D6H ;AUXILIARY-CARRY FLAG 00D5 = F0: EQU 0D5H ;USER FLAG 0 00D4 = RS1: EQU 0D4H ;REGISTER SELECT MSB 00D3 = RS0: EQU 0D3H ;REGISTER SELECT LSB 00D2 = OV: EQU 0D2H ;OVERFLOW FLAG 00D0 = P: EQU 0D0H ;PARITY FLAG 00BC = PS: EQU 0BCH ;PRIORITY SERIAL PORT 00BB = PT1: EQU 0BBH ;PRIORITY TIMER 1 00BA = PX1: EQU 0BAH ;PRIORITY EXTERNAL 1 00B9 = PT0: EQU 0B9H ;PRIORITY TIMER 0 00B8 = PX0: EQU 0B8H ;PRIORITY EXTERNAL 0 00AF = EA: EQU 0AFH ;ENABLE ALL INTERRUPT 00AC = ES: EQU 0ACH ;ENABLE SERIAL INTERRUPT 00AB = ET1: EQU 0ABH ;ENABLE TIMER 1 INTERRUPT 00AA = EX1: EQU 0AAH ;ENABLE EXTERNAL 1 INTERR 00A9 = ET0: EQU 0A9H ;ENABLE TIMER 0 INTERRUPT 00A8 = EX0: EQU 0A8H ;ENABLE EXTERNAL 0 INTERR 009F = SM0: EQU 09FH ;SERIAL MODE 0 009E = SM1: EQU 09EH ;SERIAL MODE 1 009D = SM2: EQU 09DH ;SERIAL MODE 2 009C = REN: EQU 09CH ;SERIAL RECEPTION ENABLE 009B = TB8: EQU 09BH ;TRANSMIT BIT 8 009A = RB8: EQU 09AH ;RECEIVE BIT 8 0099 = TI0: EQU $99 ; Transmit Interrupt Port 0 0098 = RI0: EQU $98 ; Receive Interrupt Port 0 008F = TF1: EQU 08FH ;TIMER 1 OVERFLOW FLAG 008E = TR1: EQU $8E ; Timer 1 Run Control 008D = TF0: EQU 08DH ;TIMER 0 OVERFLOW FLAG 008C = TR0: EQU 08CH ;TIMER 0 RUN CONTROL BIT 008B = IE1: EQU 08BH ;EXT INTERR. 1 EDGE FLAG 008A = IT1: EQU 08AH ;EXT INTERR. 1 TYPE FLAG 0089 = IE0: EQU 089H ;EXT INTERR. 0 EDGE FLAG 0088 = IT0: EQU 088H ;EXT INTERR. 0 TYPE FLAG 00C0 = RI1: EQU $C0 ; Receive Interrupt Port 1 00C1 = TI1: EQU $C1 ; Transmit Interrupt Port 1 00DF = SMOD1: EQU $DF ; Doublage baud rate port 1 00C9 = CT2: EQU $C9 ; Compteur/Timer 2 00CA = TR2: EQU $CA ; Contrôle Timer 2 00CC = TCLK2: EQU $CC ; Horloge réception port 0 sur timer 2 00CD = RCLK2: EQU $CD ; Horloge transmission port 0 sur timer 2 ; Target specific definitions 0098 = RI_MIDI: EQU RI0 ; MIDI is on port 0 0099 = TI_MIDI: EQU TI0 0099 = SBUF_MIDI: EQU SBUF0 00C0 = RI_RS: EQU RI1 ; RS232 is on port 1 00C1 = TI_RS: EQU TI1 00C1 = SBUF_RS: EQU SBUF1 0094 = RTS_RS: EQU P1+4 ; RTS line status 0095 = CTS_RS: EQU P1+5 ; CTS line control 0096 = RAZ_OVR: EQU P1+6 ; Push Button input for overflow clear 0097 = LED_OVR: EQU P1+7 ; Overflow indicator ; System variables (bytes) 0050 ORG $50 0050 CHAR_RS: DFS 1 ; Byte read on RS 0051 PTR_IN: DFS 1 ; FIFO input pointer 0052 PTR_OUT: DFS 1 ; FIFO output pointer 0053 MIDI_DATA: DFS 1 ; MIDI Byte waiting for retransmission on RS 0080 ORG $80 ; Indirect RAM = FIFO Buffer 0080 FIFO: DFS 128 ; System variables (bits) 0070 ORG $70 0070 MIDI_DATA_AVAIL: DFS 1 ; CODE Section 0000 ORG $0 0000 020003 LJMP START ; RESET vector ; **************************************** ; Microcontroller configuration ; **************************************** 0003 START: ; **************************************** ; Timer 2 is clock source for serial port 0 (31250 bauds * 16=500kHz) 0003 75C902 MOV T2MOD, #$02 ; Outputs clock for test purpose 0006 C2C9 CLR CT2 ; Source Timer 2 = Internal clock after divide / 2 0008 D2CC SETB TCLK2 ; Set Timer 2 as Baud Rate Generator 000A D2CD SETB RCLK2 000C C2CA CLR TR2 ; Freeze Timer 2 000E 75CAE8 MOV RCAP2L, #$E8 ; 65536-24=65512 (FFE8) 0011 75CBFF MOV RCAP2H, #$FF 0014 75CCE8 MOV TL2, #$E8 0017 75CDFF MOV TH2, #$FF 001A D2CA SETB TR2 ; Setup serial port 0 001C 759850 MOV SCON0, #01010000B ; **************************************** ; Timer 1 is clock source for serial port 1 (38400 * 16=614400Hz from external 1.8432MHz) 001F D2DF SETB SMOD1 ; Baud Clock divider off 0021 C28E CLR TR1 ; Freeze Timer 1 0023 758962 MOV TMOD, #$62 ; Setup Timer 1 and Timer 0 0026 758DFD MOV TH1, #253 0029 758BFD MOV TL1, #253 002C D28E SETB TR1 ; Setup serial port 1 002E 75C050 MOV SCON1, #01010000B ; **************************************** ; Setup application variables 0031 C297 CLR LED_OVR 0033 755180 MOV PTR_IN, #FIFO ; FIFO init 0036 755280 MOV PTR_OUT, #FIFO 0039 D299 SETB TI_MIDI 003B D2C1 SETB TI_RS 003D C298 CLR RI_MIDI 003F C2C0 CLR RI_RS 0041 C270 CLR MIDI_DATA_AVAIL ; No MIDI data available 0043 C295 CLR CTS_RS ; Activate CTS (allow transmission) ; Main application loop 0045 MAINLOOP: 0045 120058 LCALL GETMIDI 0048 120069 LCALL MIDI2RS 004B 120078 LCALL GETRS 004E 120096 LCALL RS2MIDI 0051 209602 JB RAZ_OVR, END_MAINLOOP ; If CLEAR pushbutton depressed 0054 C297 CLR LED_OVR ; then clears LED 0056 END_MAINLOOP: 0056 80ED JMP MAINLOOP ; ******************************************** ; GETMIDI : get MIDI Byte and store it temporarily to let RS232 buffer empty completely ; before sending it 0058 GETMIDI: 0058 30980D JNB RI_MIDI, END_GETMIDI ; MIDI Byte available 005B E599 MOV A, SBUF_MIDI ; Yes : get it 005D C298 CLR RI_MIDI 005F F553 MOV MIDI_DATA, A ; Save it 0061 D270 SETB MIDI_DATA_AVAIL ; Mark MIDI byte pending 0063 CHK_SYS_RESET: 0063 B4FF02 CJNE A, #$FF, END_GETMIDI ; If MIDI System Reset message 0066 C297 CLR LED_OVR ; then clear overflow LED 0068 END_GETMIDI: 0068 22 RET ; ******************************************** ; MIDI2RS : Send received MIDI byte to RS232 0069 MIDI2RS: 0069 30C10B JNB TI_RS, END_MIDI2RS ; If RS232 buffer empty 006C 307008 JNB MIDI_DATA_AVAIL, END_MIDI2RS ; and MIDI byte to send 006F E553 MOV A, MIDI_DATA ; Get back MIDI byte 0071 C2C1 CLR TI_RS 0073 C270 CLR MIDI_DATA_AVAIL ; Mark no MIDI byte pending 0075 F5C1 MOV SBUF_RS, A ; Send MIDI byte to RS232 0077 END_MIDI2RS: 0077 22 RET ; ******************************************** ; GETRS : Read RS received byte et store it in FIFO 0078 GETRS: 0078 30C01A JNB RI_RS, END_GETRS ; Something available on RS port ? 007B GETRS_CHAR: 007B E5C1 MOV A, SBUF_RS ; Yes : 007D F550 MOV CHAR_RS, A ; CHAR_RS:=SBUF_RS 007F C2C0 CLR RI_RS ; Prepare uC for next RS byte 0081 CHK_FIFO: ; Enough room in FIFO ? 0081 E551 MOV A, PTR_IN ; Yes : 0083 04 INC A ; A:=PTR_IN+1 0084 7002 JNZ NO_LOOP_IN ; If FIFO loop back 0086 7480 MOV A, #FIFO ; then A:=Debut file 0088 NO_LOOP_IN: 0088 B55204 CJNE A, PTR_OUT, FIFO_LIBRE ; Compare A with PTR_OUT 008B FIFO_PLEIN: ; FIFO is full : 008B D297 SETB LED_OVR ; Show the problem to user 008D 8006 JMP END_GETRS 008F FIFO_LIBRE: ; FIFO is not full : 008F F551 MOV PTR_IN, A ; PTR_IN:=Computed pointer 0091 F8 MOV R0, A 0092 E550 MOV A, CHAR_RS 0094 F6 MOV @R0, A ; FIFO[PTR_IN]:=CHAR_RS 0095 END_GETRS: 0095 22 RET ; ******************************************** ; RS2MIDI : Send to MIDI datas stored in FIFO if MIDI port is free 0096 RS2MIDI: 0096 E552 MOV A, PTR_OUT ; Something waiting in FIFO ? 0098 B55102 CJNE A, PTR_IN, DATA_IN_FIFO ; Yes if PTR_IN<>PTR_OUT 009B 8010 JMP END_RS2MIDI 009D DATA_IN_FIFO: 009D 04 INC A ; Compute pointer to next data 009E 7002 JNZ NO_LOOP_OUT ; If FIFO end is reached 00A0 7480 MOV A, #FIFO ; return to beginning 00A2 NO_LOOP_OUT: 00A2 309908 JNB TI_MIDI, END_RS2MIDI ; If MIDI buffer not empty, leave process (PTR_OUT is not yet affected) 00A5 C299 CLR TI_MIDI 00A7 SBUF_MIDI_VIDE: 00A7 F552 MOV PTR_OUT, A ; Store new pointer value 00A9 F8 MOV R0, A 00AA E6 MOV A, @R0 ; Get data waiting in FIFO 00AB F599 MOV SBUF_MIDI, A ; Send it on MIDI 00AD END_RS2MIDI: 00AD 22 RET 0000 END 00D6 AC 00E0 ACC 00F0 B 0050 CHAR_RS 0081 CHK_FIFO 0063 CHK_SYS_RESET 00C9 CT2 0095 CTS_RS 00D7 CY 009D DATA_IN_FIFO 0083 DPH 0082 DPL 00AF EA 0068 END_GETMIDI 0095 END_GETRS 0056 END_MAINLOOP 0077 END_MIDI2RS 00AD END_RS2MIDI 00AC ES 00A9 ET0 00AB ET1 00A8 EX0 00AA EX1 00D5 F0 0080 FIFO 008F FIFO_LIBRE 008B FIFO_PLEIN 0058 GETMIDI 0078 GETRS 007B GETRS_CHAR 0089 IE0 008B IE1 00A8 IEC 00B8 IPC 0088 IT0 008A IT1 0097 LED_OVR 0045 MAINLOOP 0069 MIDI2RS 0053 MIDI_DATA 0070 MIDI_DATA_AVAIL 0088 NO_LOOP_IN 00A2 NO_LOOP_OUT 00D2 OV 00D0 P 0080 P0 0090 P1 00A0 P2 00B0 P3 0087 PCON 00BC PS 00D0 PSW 00B9 PT0 00BB PT1 0051 PTR_IN 0052 PTR_OUT 00B8 PX0 00BA PX1 0096 RAZ_OVR 009A RB8 00CB RCAP2H 00CA RCAP2L 00CD RCLK2 009C REN 0098 RI0 00C0 RI1 0098 RI_MIDI 00C0 RI_RS 00D3 RS0 00D4 RS1 0096 RS2MIDI 0094 RTS_RS 0099 SBUF0 00C1 SBUF1 0099 SBUF_MIDI 00A7 SBUF_MIDI_VIDE 00C1 SBUF_RS 0098 SCON0 00C0 SCON1 009F SM0 009E SM1 009D SM2 00DF SMOD1 0081 SP 0003 START 00C8 T2CON 00C9 T2MOD 009B TB8 00CC TCLK2 0088 TCON 008D TF0 008F TF1 008C TH0 008D TH1 00CD TH2 0099 TI0 00C1 TI1 0099 TI_MIDI 00C1 TI_RS 008A TL0 008B TL1 00CC TL2 0089 TMOD 008C TR0 008E TR1 00CA TR2