From 8b71fafb84f14763787a5fab5590c69cc7dccc9a Mon Sep 17 00:00:00 2001 From: Colin Leroy-Mira Date: Mon, 19 Feb 2024 21:30:26 +0100 Subject: [PATCH] IIgs SCC: Allow choosing 115200bps as the card allows it Of course, that won't work full speed with the standard IRQ-based RX. But that will allow users to setup the port at this speed without duplicating the setup part of the code. Up to them to add hooks to disable IRQs and read directly in a tight asm loop. --- libsrc/apple2/ser/a2.gs.s | 66 +++++++++++++++++++++++++++++---------- 1 file changed, 49 insertions(+), 17 deletions(-) diff --git a/libsrc/apple2/ser/a2.gs.s b/libsrc/apple2/ser/a2.gs.s index 3a2db1926..c53fe7ecb 100644 --- a/libsrc/apple2/ser/a2.gs.s +++ b/libsrc/apple2/ser/a2.gs.s @@ -66,6 +66,8 @@ HSType: .res 1 ; Flow-control type RecvBuf: .res 256 ; Receive buffers: 256 bytes SendBuf: .res 256 ; Send buffers: 256 bytes +ClockSource: .res 1 ; Whether to use BRG or XTAL for clock + .data Opened: .byte $00 ; 1 when opened @@ -106,6 +108,15 @@ TxBitTable: .byte %00000000 ; SER_BITS_5, in WR_TX_CTRL (WR5) .rodata +ClockMultiplier:.byte %01000000 ; Clock x16 (300-57600bps, ref page 5-8) + .byte %10000000 ; Clock x32 (115200bps, ref page 5-8) + +ClockSourceA: .byte %11010000 ; Use baud rate generator (page 5-17) + .byte %10000000 ; Use XTAL (115200bps) + +ClockSourceB: .byte %01010000 ; Use baud rate generator + .byte %00000000 ; Use XTAL (115200bps) + BaudTable: ; bit7 = 1 means setting is invalid ; Otherwise refers to the index in ; Baud(Low/High)Table @@ -127,7 +138,7 @@ BaudTable: ; bit7 = 1 means setting is invalid .byte $05 ; SER_BAUD_19200 .byte $06 ; SER_BAUD_38400 .byte $07 ; SER_BAUD_57600 - .byte $FF ; SER_BAUD_115200 + .byte $00 ; SER_BAUD_115200 .byte $FF ; SER_BAUD_230400 StopTable: .byte %00000100 ; SER_STOP_1, in WR_TX_RX_CTRL (WR4) @@ -180,7 +191,6 @@ RX_CTRL_OFF = %11111110 ; ANDed,Rx disabled WR_TX_RX_CTRL = 4 RR_TX_RX_STATUS = 4 -TX_RX_CLOCK_MUL = %01000000 ; Clock x16 (Ref page 5-8) WR_TX_CTRL = 5 ; (Ref page 5-9) RR_TX_STATUS = 5 ; Corresponding status register @@ -197,15 +207,13 @@ MASTER_IRQ_MIE_RST = %00001010 ; STA'd MASTER_IRQ_SET = %00011001 ; STA'd WR_CLOCK_CTRL = 11 ; (Ref page 5-17) -CLOCK_CTRL_CH_A = %11010000 -CLOCK_CTRL_CH_B = %01010000 WR_BAUDL_CTRL = 12 ; (Ref page 5-18) WR_BAUDH_CTRL = 13 ; (Ref page 5-19) WR_MISC_CTRL = 14 ; (Ref page 5-19) -MISC_CTRL_RATE_GEN_ON = %00000001 ; ORed -MISC_CTRL_RATE_GEN_OFF = %11111110 ; ANDed +MISC_CTRL_RATE_GEN_ON = %00000001 ; STA'd +MISC_CTRL_RATE_GEN_OFF = %00000000 ; STA'd WR_IRQ_CTRL = 15 ; (Ref page 5-20) IRQ_CLEANUP_EIRQ = %00001000 @@ -329,6 +337,16 @@ IIgs: : txa ; Promote char return value rts +getClockSource: + ldy #SER_PARAMS::BAUDRATE + lda (ptr1),y ; Baudrate index - cc65 value + ldy #$01 + cmp #SER_BAUD_115200 + beq :+ + ldy #$00 +: sty ClockSource + rts + ;---------------------------------------------------------------------------- ; SER_OPEN: A pointer to a ser_params structure is passed in ptr1. ; Must return an SER_ERR_xx code in a/x. @@ -364,6 +382,8 @@ SER_OPEN: lda #$00 jsr writeSCCReg + jsr getClockSource ; Should we use BRG or XTAL? + ldy #SER_PARAMS::STOPBITS lda (ptr1),y ; Stop bits tay @@ -377,16 +397,18 @@ SER_OPEN: ora ParityTable,y ; Get value bmi InvParam - ora #TX_RX_CLOCK_MUL + ldy ClockSource ; Setup clock multiplier + ora ClockMultiplier,y ldy #WR_TX_RX_CTRL ; Setup stop & parity bits jsr writeSCCReg + ldy ClockSource cpx #CHANNEL_B bne ClockA ClockB: + lda ClockSourceB,y ldy #WR_CLOCK_CTRL - lda #CLOCK_CTRL_CH_B jsr writeSCCReg lda #INTR_PENDING_RX_EXT_B ; Store which IRQ bits we'll check @@ -394,8 +416,8 @@ ClockB: bra SetBaud ClockA: + lda ClockSourceA,y ldy #WR_CLOCK_CTRL - lda #CLOCK_CTRL_CH_A jsr writeSCCReg lda #INTR_PENDING_RX_EXT_A ; Store which IRQ bits we'll check @@ -411,11 +433,16 @@ SetBaud: InvParam: lda #SER_ERR_INIT_FAILED - ldy #$00 ; Mark port closed - bra SetupOut + ldx #$00 ; Promote char return value + stz Opened ; Mark port closed + cli + rts BaudOK: tay + cpy #SER_BAUD_115200 + beq :+ ; Skip baud rate generator setup: + ; For 115200bps, we use XTAL instead lda BaudLowTable,y ; Get low byte @@ -428,8 +455,13 @@ BaudOK: ldy #WR_BAUDH_CTRL jsr writeSCCReg - ldy #WR_MISC_CTRL ; Time to turn this thing on - lda #MISC_CTRL_RATE_GEN_ON +: lda #MISC_CTRL_RATE_GEN_ON ; Setup BRG according to selected rate + ldy ClockSource + cpy #$00 + beq :+ + lda #MISC_CTRL_RATE_GEN_OFF + +: ldy #WR_MISC_CTRL ; Time to turn this thing on jsr writeSCCReg ldy #SER_PARAMS::DATABITS @@ -486,11 +518,11 @@ StoreFlag: sta SER_FLAG ldy #$01 ; Mark port opened - lda #SER_ERR_OK - -SetupOut: - ldx #$00 ; Promote char return value sty Opened + + lda #SER_ERR_OK + ldx #$00 ; Promote char return value + cli rts