LSI LSI53C896, Technical Manual

Page: 178 / 370

4-66 Registers
Register: 0x27
DMA Command (DCMD)
Read/Write
DCMD DMA Command [7:0]
This 8-bit register determines the instruction for the
LSI53C896 SCSI function to execute. This register has a
different format for each instruction. For a complete
description see
Chapter 5, “SCSI SCRIPTS Instruction
Set.”
Registers: 0x28–0x2B
DMA Next Address (DNAD)
Read/Write
DNAD DMA Next Address [31:0]
This 32-bit register contains the general purpose address
pointer. At the start of some SCRIPTS operations, its
value is copied from the
DMA SCRIPTS Pointer Save
(DSPS) register. Its value may not be valid except in
certain abort conditions. The default value of this register
is zero.
Registers: 0x2C–0x2F
DMA SCRIPTS Pointer (DSP)
Read/Write
DSP DMA SCRIPTS Pointer [31:0]
To execute SCSI SCRIPTS, the address of the first
SCRIPTS instruction must be written to this register. In
7 0
DCMD
x x x x x x x x
31 0
DNAD
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
31 0
DSP
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
*