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rdwt.asm
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Assembly Source File
|
1992-12-24
|
6KB
|
249 lines
;
;
; BUSY check on SELECT
; improved handshake on MSGIN, CMDOUT
;
; 26 May 1992 TM
; 17 Jun 1992 TM SCSI BUSY FLAG ADDED for simaltaneous copy bug
; 15 Sep 1992 TM GENERIC version
; 04 Oct 1992 HL Selection timeout return status added
; Normal return status zero added
; Removal of "15(a1)" accesses
;
include "exec/types.i"
include "exec/io.i"
include "exec/devices.i"
include "exec/tasks.i"
include "exec/interrupts.i
include "devices/scsidisk.i"
include "mydev.i"
include "scsi.i"
Public SCSIRdWt
SCSIRdWt:
bset.b #3,NCR+4 ;TM!!! EOP INTERRUPT bit is used for
bne.s SCSIRdWt ;TM!!! SCSI BUSY FLAG
move.b #$08,NCR+4 ;TM!!!
movem.l d4-d7/a1-a5,-(sp) ;save regs
move.l #CMDBUF,a1 ;get CMDBUF add
move.l d2,d5 ;copy unit#
moveq #$0,d2 ;LU=0
lsr.l #1,d5 ;create Target address
bcc.s Drive
moveq #$20,d2 ;LU=1
STILLbsy1:
btst.b #6,NCR+8 ; TM BUSY check
bne.s STILLbsy1 ; TM wait if still busy
Drive:
moveq #$1,d4
lsl.l d5,d4 ;shift to address bit
or.b #$80,d4 ;add addresses
move.b d4,NCR ;load addresses
move.b #$5,NCR+2 ;assert BUS with address
;build the scsi cmd packet
move.l d1,d4 ;get the start sect #
move.l d0,d5 ;get the #bytes to transfere
asr.l #8,d5 ;shift 9 palces to get sectors
asr.l #1,d5
and.l #$FF,d5 ;must be less than 1 byte
; asl.l #8,d5 ;move to upper byte in word; TM to enable NEC cache
; move.w d5,4(a1) ;place in packet ; TM
move.b d5,4(a1) ;place in packet ; TM don't mask last byte
asr.l #8,d4 ;convert to sectors
asr.l #1,d4
and.l #$000FFFFF,d4 ;mask out L U #
move.l d4,(a1) ;place in packet
;add the logical unit #
or.b d2,1(a1) ;put LU# in the packet
cmp.w #CMD_READ,IO_COMMAND(a2) ;read ?
bne WriteSCSI
move.b #$08,(a1) ;set cmd to read
Selection:
bsr SELph ;select the target
End:
bclr.b #3,NCR+4 ;TM!!! clear SCSI BUSY FLAG
movem.l (sp)+,d4-d7/a1-a5 ;restore regs
rts ;return to caller
WriteSCSI: ;send data to the SCSI
move.b #$0a,(a1)
bra.s Selection
SELph: ;select the target
move.l #M250,d5 ;load timer
loop1: btst.b #6,NCR+8 ;test BSY
bne.s SLECT ;if busy , selected
subq #1,d5 ;dec timer
bne.s loop1 ;loop
; move.b #$01,15(a1) ;set drive not ready error ; HL
move.b #HFERR_SelTimeout,d0 ; HL
rts
SLECT:
and.b #$FB,NCR+2 ;clr SEL
NextPhase: ;Check the SCSI bus phase
move.b #$0,NCR
move.b #$0,NCR+6 ;clear TCR
btst.b #5,NCR+8 ;test REQ
bne.s GotREQ ;if REQ it must be busy...
btst.b #6,NCR+8 ;check BUSY
beq Done ;bus free
bra NextPhase ; still waiting for REQ
GotREQ:
btst.b #3,NCR+8 ;check C/D
beq.s Dat ;data in/out phase
btst.b #4,NCR+8 ;check MSG
bne.s Message ;Message in/out phase
btst.b #2,NCR+8 ;check I/O
bne.s STATph ;stat phase
bra.s CMDph ;command phase
Message: ;check to see if it is message in or out
btst.b #2,NCR+8 ;check I/O
; bne.s MSGINph
bne MSGINph ;TM
; bra.s MSGOUTph ;TM
bra MSGOUTph ;TM
Dat: ;check to see if it is data in or out
btst.b #2,NCR+8 ;check I/O
; bne.s RDATph
bne RDATph ;TM
; bra.s SDATph ;TM
bra SDATph ;TM
CMDph: ;send command
move.l #CMDBUF,a4 ;set the cmd buffer add
move.b #$02,NCR+6 ;set TCR to command phase
Send: ;send x characters to the target
btst.b #6,NCR+8 ;TM busy check
beq Done ;TM busy check
btst.b #5,NCR+8 ;test for REQ
beq.s Send ;wait for REQ
btst.b #3,NCR+10 ;test phase match
; beq.s NextPhase
beq NextPhase ;TM
move.b (a4)+,NCR ;set the byte
ori.b #$10,NCR+2 ;set ACK
CMDReq:
btst.b #6,NCR+8 ;TM busy check
beq Done ;TM busy check
btst.b #5,NCR+8 ; TM test for REQ
bne.s CMDReq ; TM wait for REQ deasserted
andi.b #$EF,NCR+2 ;clr ACK
bra Send
STATph: ;get status byte
ori.b #$10,NCR+2 ;set ACK
STATReq:
btst.b #6,NCR+8 ;TM busy check
beq Done ;TM busy check
btst.b #5,NCR+8 ; TM test for REQ
bne.s STATReq ; TM wait for REQ deasserted
andi.b #$ef,NCR+2 ;clr ACK
bra NextPhase
MSGINph: ;only msg supported is COMPLETE..so we just ack it
ori.b #$10,NCR+2 ;set ACK
MSGINReq:
btst.b #6,NCR+8 ;TM busy check
beq Done ;TM busy check
btst.b #5,NCR+8 ; TM test for REQ
bne.s MSGINReq ; TM wait for REQ deasserted
and.b #$EF,NCR+2 ;clr ACK
STILLbsy:
btst.b #6,NCR+8 ; TM BUSY check
bne.s STILLbsy ; TM wait if still busy
Done: ;did we end normally ?
clr.l d0 ; HL
rts ;do a clean end
MSGOUTph: ;send message to target
bra NextPhase ;error try again
SDATph: ;send data to target
move.l a0,a4 ;set the data buffer add
move.b #$00,NCR+6 ;set TCR to send data
SendData: ;send x characters to the target
btst.b #6,NCR+8 ;TM busy check
beq Done ;TM busy check
btst.b #5,NCR+8 ;test for REQ
beq.s SendData ;wait for REQ
btst.b #3,NCR+10 ;test phase match
; beq.s NextPhase
beq NextPhase ;TM
; move.b #$02,NCR+4 ;Set DMAMODE
bset.b #1,NCR+4 ;TM!!!
move.b #$00,NCR+12 ;start DMA recieve
moveq #64,d4 ;load counter..we do 512 byte blocks
LoopTop:
move.b (a4)+,DMA ;set byte 0
move.b (a4)+,DMA ;set byte 1
move.b (a4)+,DMA ;set byte 2
move.b (a4)+,DMA ;set byte 3
move.b (a4)+,DMA ;set byte 4
move.b (a4)+,DMA ;set byte 5
move.b (a4)+,DMA ;set byte 6
move.b (a4)+,DMA ;set byte 7
subq #1,d4
bne.s LoopTop
; move.b #$0,NCR+4 ;clear DMAMODE
bclr.b #1,NCR+4 ;TM!!!
bra SendData
RDATph: ;receive data fron target
move.l a0,a4 ;set the data buffer add
lea DMA+12,a5 ;set DMA recieve Base
move.b #$01,NCR+6 ;set TCR to receive data
RecData:
; move.b #$02,NCR+4 ;Set DMAMODE
bset.b #1,NCR+4 ;TM!!!
move.b #$00,NCR+14 ;start DMA recieve
moveq #63,d4 ;load counter..we do 512 byte blocks
RecLoop:
move.b (a5),(a4)+
move.b (a5),(a4)+
move.b (a5),(a4)+
move.b (a5),(a4)+
move.b (a5),(a4)+
move.b (a5),(a4)+
move.b (a5),(a4)+
move.b (a5),(a4)+
subq #1,d4 ;decrement counter
bne.s RecLoop ;done with block?
move.b (a5),(a4)+
move.b (a5),(a4)+
move.b (a5),(a4)+
move.b (a5),(a4)+
move.b (a5),(a4)+
move.b (a5),(a4)+
move.b (a5),(a4)+
; move.b #$0,NCR+4 ;disable ack/req
bclr.b #1,NCR+4 ;TM!!!
move.b (a5),(a4)+ ;read last byte of block
WRec:
btst.b #5,NCR+8 ;test REQ
bne.s RReq ;Got it
btst.b #6,NCR+8 ;check BUSY
beq Done ;Not Busy? must be Done.
bra.s WRec ;wait for REQ
RReq:
btst.b #3,NCR+10 ;test for phase match
beq NextPhase
bra.s RecData
CMDBUF dc.b $0A,$00,$00,$00,$01,$00,$00,$00,$00,$00 ; TM GENERIC
;CMDBUF dc.b $0A,$00,$00,$00,$01,$0c,$00,$00,$00,$00 ; TM for NEC cache
STAT ds.b $01 ;status word
MSGINBUF ds.b $04 ;message buffer
ERROR ds.b $01 ;error flag
;
;
END