Hardware Description
SYS68K/CPU-30 R4 Technical Reference Manual
Page 82
3.11.3.2 DMA Transfer
Programming
Example
3.11.4 The SCSIbus
3.11.4.1 SCSIbus
Configuration
Communication on the SCSIbus is only allowed between two SCSI
devices at any given time. There may be a maximum of eight SCSI
devices. Each SCSI device has a SCSI ID bit assigned. When two SCSI
devices communicate on the SCSIbus, one acts as an initiator, and the
target performs the operation. A SCSI device usually has a fixed role as
an initiator or target, but some devices may be able to assume either role.
An initiator may address up to seven peripheral devices that are
connected to a target. An option allows the addressing of up to 2048
peripheral devices per target using extended messages.
Of the eight SCSI devices supported on the SCSIbus, there can be any
combination of initiators and targets. Certain SCSIbus functions are
assigned to the initiator and other functions are assigned to the target. The
initiator may arbitrate for the SCSIbus and select a particular target. The
target may request the transfer of COMMAND, DATA, STATUS, or
other information on the data bus, and in some cases, it may arbitrate for
the SCSIbus and reselect an initiator for the purpose of continuing an
operation.
*---------------------------------------------------------------
* DATA OUTPUT TO SCSI TARGET, USING THE MB87033/34 AND THE
* FGA-002 DMA CHANNEL
*---------------------------------------------------------------
:
BCLR #$07,PBDR+PI_T ;SELECT DMA WORKS WITH SCSI
BCLR #$06,PBDR+PI_T ;SELECT TRANSFER DMA TO SCSI
* THE FOLLOWING AUX VALUES ARE ONLY VALID FOR THE CPU-30 !
MOVE.B #$00,FGA02+AUXPINC ;AUX PIN CONTROL
MOVE.B #$30,FGA02+AUXDST ;AUXDSTSTART
MOVE.B #$45,FGA02+AUXDTE ;AUXDSTTERM
MOVE.B #$00,FGA02+AUXDSTR ;AUXDSTWEX
MOVE.L #BCOUNT,FGA02+DMABCNT ;BYTE COUNT
MOVE.L #SADDR,FGA02+DMASADR ;DMA SOURCE ADDR
MOVE.B #$C5,FGA02+DMASATR ;DMA SOURCE ATTRIBUTE (DPR)
MOVE.B #$C8,FGA02+DMADATR ;DMA DEST ATTRIBUTE (AUX)
MOVE.B #$41,FGA02+DMAGEN ;DMA GENERAL CONTROL
:
MOVE.B #$00,SCSI+TMODREG ;SET SCSI TRANSFER MODE
MOVE.B #$80,SCSI+SCMDREG ;SCSI COMMAND
BCLR #$00,PCDR+PI_T2 ;SET TO DMA ACTIVE
MOVE.B #$01,FGA02+DMARUNC ;START DMA CONTROLLER
WAIT TST.B FGA02+DMARUNC ;POLL ON DMA READY
BMI.B WAIT
BSET #$00,PI_T2+PCDR ;SET TO CPU ACTIVE
:
Содержание SYS68K/CPU-30 R4
Страница 41: ...Installation SYS68K CPU 30 R4 Technical Reference Manual Page 28...
Страница 127: ...Hardware Description SYS68K CPU 30 R4 Technical Reference Manual Page 114...
Страница 130: ...SYS68K CPU 30 R4 Technical Reference Manual Set of Data Sheets Page 117 4 2 1 RTC 72421...
Страница 131: ...Set of Data Sheets SYS68K CPU 30 R4 Technical Reference Manual Page 118 4 2 2 DUSCC 68562...
Страница 132: ...SYS68K CPU 30 R4 Technical Reference Manual Set of Data Sheets Page 119 4 2 3 PI T TS68230...
Страница 133: ...Set of Data Sheets SYS68K CPU 30 R4 Technical Reference Manual Page 120 4 2 4 SCSI 87033 34...
Страница 134: ...SYS68K CPU 30 R4 Technical Reference Manual Set of Data Sheets Page 121 4 2 5 FDC37C65C...
Страница 135: ...Set of Data Sheets SYS68K CPU 30 R4 Technical Reference Manual Page 122 4 2 6 LANCE Am79C90...
Страница 136: ...SYS68K CPU 30 R4 Technical Reference Manual Set of Data Sheets Page 123 4 2 7 SIA Am7992B...
Страница 137: ...Set of Data Sheets SYS68K CPU 30 R4 Technical Reference Manual Page 124 4 2 8 Motorola MC68030 and MC68882...
Страница 145: ...VMEPROM SYS68K CPU 30 R4 Technical Reference Manual Page 132...
Страница 189: ...Appendix to VMEPROM SYS68K CPU 30 R4 Technical Reference Manual Page 176...