{File: [Iris]DLion>SIOSubs.asm Modification History: Dennis Grundler: 1-Sep-84 17:15:51 Added copyright notice. Mike Thatcher: 16-Mar-84 10:25:09 Fix SetBaud so OSC gets enabled/disabled as appropriate. Jim Frandeen : May 25, 1982 3:57 PM Created by Jim Frandeen : March 25, 1982 8:58 AM } { Copyright (C) 1982, 1984 by Xerox Corporation. All rights reserved.} Get "SysDefs.asm" Get "CommonDefs.asm" Get "RS232CDefs.asm" IMP AsyncTimerValue ;From RS232CInterrupts IMP CurrentRS366Status ;From RS232CMisc IMP RxWR1 ;From Rs232CMisc IMP RxWR3 ;From Rs232CMisc IMP RxWR4 ;From Rs232CMisc IMP TxWR1 ;From Rs232CMisc IMP TxWR4 ;From Rs232CMisc IMP TxWR5 ;From Rs232CMisc EXP AsynchronousDivisor EXP AsyncTimerCounter EXP AsyncTimerStoppedFlag EXP BisyncTimerTable EXP HLPlus2A EXP ResetChannels EXP SetAsyncTimer EXP SetBaudRate EXP SetRS366 EXP SynchronousDivisor EXP TestAsyncTimer ; SetAsyncTimer: {This entry is called whenever a new timeout value is set. This is called by Misc when we get a SetParameters command. The client supplies the timeout value in RS232CParameer4. We set the TimerStoppedFlag.} STA AsyncTimerStoppedFlag ; set/reset timer stopped flag SHLD AsyncTimerValue ; set initial iteration counter value SHLD AsyncTimerCounter ; set iteration counter StartAsyncTimer: {This entry is called by TestAsyncTimer when we get a timeout. We restart the timer.} MVI A,0B0H ;timer channel 2, mode 0, binary OUT TimerMode LXI H,TimerCount2+8000H MVI M,0FEH ;Send low byte of 1840 decimal MVI M,47H ;Send high byte RET TestAsyncTimer: {This entry is called by the Async Get Loop while we are waiting for the interrupt routine to fill a frame. When we get a timeout, we end the current frame. Note that we will not get a timeout until we have received at least one character because the TimerStoppedFlag is set until we receive the first character. When we return: Condition Flag = Zero if timeout Condition Flag # Zero if no timeout } DB opMVIA ;A Ź AsyncTimerStoppedFlag AsyncTimerStoppedFlag: DB 0 ORA A RNZ ; if timer not running {Continue if timer is running. AsyncTimerStoppedFlag=0.} IN IntReq ; read timer service request register ANI MiscTimerReqMask ; test timer output RNZ ; if timer output not active (Z flag false!) {Continue if 1 msc timeout.} CALL StartAsyncTimer ; restart timer chip DB opLXIH ;HL Ź AsyncTimerCounter AsyncTimerCounter: DW 0 DCX H ; update iteration counter MOV A,L ORA H JNZ TestAsyncTimer10 ; if iteration counter not exhausted LHLD AsyncTimerValue ; - else restart with initial value TestAsyncTimer10: SHLD AsyncTimerCounter ; update iteration counter RNZ ;No timeout {Continue if timeout. Set the TimerStoppedFlag.} CMA ;A Ź FF STA AsyncTimerStoppedFlag ; set timer stopped flag RET ; Z flag set if timeout occurred ; ResetChannels: {Reset Rx and Tx channels. If the DMA Channel2 is being used for Rx, or if DMA Channel3 is being used for Tx, disable these also. This subroutine is called by Off and by SetParameters.} MVI A,ChannelReset DI OUT TxCont OUT RxCont EI RET ; SetBaudRate: { This Routine sets the Frequency Divisor and Oscillation Mode for the i8253 Programmable Interval Timer. Counter #1 of i8253 is used for the Tx Clock generator, #2 is used for the Rx generator.On entry, HL points to Baud rate divisor table: AsynchronousDivisor or SynchronousDivisor.} CALL HLPlus2A MVI A,OSCCMD ; Frequncy and Mode Set to i8253 OUT OSCCont ; Counter#1, LSB & MSB, Mode3, Binary MOV A,M ; A Ź ((H,L)) OUT OSCReg INX H ; H,L Ź (H,L)+1 MOV A,M ; A Ź ((H,L)) OUT OSCReg XRA A ; A Ź 0 {Fall thru to RS366 to Enable/Disable OSC clock } SetRS366: {Set the RS366 register to the value in A. We do this for the SetRS366Status command. This comes from the SetStatus366 procedure in the head. Parameter bits are as follows: 10 callRequest 11 digitPresent 12..15 digit The two high order bits are not disturbed: 8 test loop back enable bit 9 local OSC Enable bit } XRI RS366InvMask ;30H MOV D,A LDA CurrentRS366Status ; Read Current RS366 Status ANI RS366ResetMask ; Save Loop connection and Clock Sel. ORA D OUT RS366Reg RET ; HLPlus2A: { On entry: A = number to add to HL. On exit: HL = HL + 2A } ADD A ;A*2 Makes Table Reference Address MOV E,A MVI D,0 DAD D ;HL Ź (H,L)+(B,C) RET AsynchronousDivisor: DW 2304 ; Divisor for 50Hz Asynchronus mode DW 1536 ; Divisor for 75Hz Asynchronus mode DW 1047 ; Divisor for 110Hz Asynchronus mode DW 856 ; Divisor for 134.5Hz Asynchronus mode DW 768 ; Divisor for 150Hz Asynchronus mode DW 384 ; Divisor for 300Hz Asynchronus mode DW 192 ; Divisor for 600Hz Asynchronus mode DW 96 ; Divisor for 1200Hz Asynchronus mode DW 48 ; Divisor for 2400Hz Asynchronus mode DW 32 ; Divisor for 3600Hz Asynchronus mode DW 24 ; Divisor for 4800Hz Asynchronus mode DW 16 ; Divisor for 7200Hz Asynchronus mode DW 12 ; Divisor for 9600Hz Asynchronus mode DW 6 ; Divisor for 19200Hz Asynchronus mode DW 3 ; Divisor for 38400Hz Asynchronus mode DW 2 ; Divisor for 57600Hz Asynchronus mode SynchronousDivisor: DW 36864 ; Divisor for 50Hz Synchronus mode DW 24576 ; Divisor for 75Hz Synchronus mode DW 16756 ; Divisor for 110Hz Synchronus mode DW 13704 ; Divisor for 134.5Hz Synchronus mode DW 12288 ; Divisor for 150Hz Synchronus mode DW 6144 ; Divisor for 300Hz Synchronus mode DW 3072 ; Divisor for 600Hz Synchronus mode DW 1536 ; Divisor for 1200Hz Synchronus mode DW 768 ; Divisor for 2400Hz Synchronus mode DW 512 ; Divisor for 3600Hz Synchronus mode DW 384 ; Divisor for 4800Hz Synchronus mode DW 256 ; Divisor for 7200Hz Synchronus mode DW 192 ; Divisor for 9600Hz Synchronus mode BisyncTimerTable: DW 50 ; 50Baud 1 Sec DW 75 ; 75Baud 1 Sec DW 110 ; 110Baud 1 Sec DW 135 ; 134.5Baud 1 Sec DW 150 ; 150Baud 1 Sec DW 300 ; 300Baud 1 Sec DW 600 ; 600Baud 1 Sec DW 1200 ; 1200Baud 1 Sec DW 2400 ; 2400Baud 1 Sec DW 3600 ; 3600Baud 1 Sec DW 4800 ; 4800Baud 1 Sec DW 7200 ; 7200Baud 1 Sec DW 9600 ; 9600Baud 1 Sec DW 19200 ; 19200Baud 1 Sec END (1792)