Dma command (dcmd), Bit is clear, the, Next address (dnad) – Avago Technologies LSI53C825AE User Manual
Page 151: Dma next address (dnad)
Operating Registers
4-63
Register: 0x27 (0xA7)
DMA Command (DCMD)
Read/Write
DCMD
DMA Command
[7:0]
This 8-bit register determines the instruction for the
LSI53C825A to execute. This register has a different
format for each instruction. For a complete description
see
Chapter 5, “SCSI SCRIPTS Instruction Set.”
Register: 0x28–0x2B (0xA8–0xAB)
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
register. Its value may not be valid except in
certain abort conditions. The default value of this register
is zero.
This register should not be used to determine data
addresses during a Phase Mismatch interrupt, as its
value is not always correct for this use. The
,
, and
registers should be used to
calculate residual byte counts and addresses as
described in the Data Paths section 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