Avago Technologies LSI53C896 - Manual (Page 233)

Block Move Instructions 5-5
Version 3.3 Copyright © 1998–2003 by LSI Logic Corporation. All rights reserved.
5.2 Block Move Instructions
For Block Move instructions, bits 5 and 4 (SIOM and DIOM) in the
DMA Mode (DMODE) register determine whether the source/destination
address resides in memory or I/O space. When data is moved onto the
SCSI bus, SIOM controls whether that data comes from I/O or memory
space. When data is moved off of the SCSI bus, DIOM controls whether
that data goes to I/O or memory space.
5.2.1 First Dword
Figure 5.2 Block Move Instruction – First Dword
IT[1:0] Instruction Type-Block Move [31:30]
IA Indirect Addressing 29
Direct
When this bit is cleared, user data is moved to or from
the 32-bit data start address for the Block Move
instruction. The value is loaded into the chip’s address
register and incremented as data is transferred. The
address of the data to move is in the second Dword of
this instruction.
When the EN64DBMV bit in Chip Control 1 (CCNTL1) is
set, a third Dword is fetched to provide the upper Dword
of a 64-bit address. The upper Dword address is fetched
along with the instruction and loaded into the
Dynamic Block Move Selector (DBMS) register.
If the EN64DBMV bit is cleared, then the upper Dword
address is pulled from the
Static Block Move Selector (SBMS) register.
The byte count and absolute address are as follows:
31 30 29 28 27 26 24 23 0
DCMD Register DBC Register
IT[1:0] IA TIA OPC SCSIP[2:0] TC[23:0]