1 first dword, First dword, Load and store instruction – first dword – Avago Technologies LSI53C1010R User Manual
Page 288
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SCSI SCRIPTS Instruction Set
Version 2.2
Copyright © 2000–2003 by LSI Logic Corporation. All rights reserved.
The SIOM and DIOM bits in the
register determine
whether the destination or source address of the instruction is in Memory
space or I/O space, as illustrated in the following table. The Load/Store
utilizes the PCI commands for I/O read and I/O write to access the
I/O space.
5.7.1 First Dword
This section describes the first Dword of the Load and Store Instruction
register.
Figure 5.15 Load and Store Instruction – First Dword
IT[2:0]
Instruction Type
[31:29]
These bits should be 0b111, indicating the Load and
Store instruction.
DSA
DSA Relative
28
When this bit is cleared, the value in the
DMA SCRIPTS Pointer Save (DSPS)
is the actual 32-bit
memory address that performs the Load/Store to/from.
When this bit is set, the chip determines the memory
Bits A1, A0
Number of Bytes Allowed to Load/Store
00
One, two, three or four
01
One, two, or three
10
One or two
11
One
Bit
Source
Destination
SIOM (Load)
Memory
Register
DIOM (Store)
Register
Memory
31
29
28
27 26 25 24 23
16 15
3
2
0
DCMD Register
DBC Register
IT[2:0]
DSA
R
NF LS
A[7:0]
R
BC
1
1
1
x
0
0
x
x
x
x
x
x
x
x
x
x
0
0
0
0
0
0
0
0
0
0
0
0
0
x
x
x