LSI LSI53C896, Technical Manual

Page: 236 / 370

5-8 SCSI SCRIPTS Instruction Set
If the enable 64-bit Table Indirect Block Move
(EN64TIBMV) bit is set and the 64-bit Table Indirect Index
Mode (64TIMOD) bit is cleared, then bits [28:24] of the
first Dword of the table entry (where the byte count is
located) will select one of the 16 scratch registers or any
of the six 64-bit selector registers (for a total of
22 selector choices) as a selector for the upper 32-bit
address. Please see the Table Indirect Index mode
mapping table for a breakdown of index values and the
corresponding registers selected. The selected address
will get loaded into the
DMA Next Address 64 (DNAD64)
automatically.
Note: If EN64TIBMV is set and 64TIMOD is set then bits [31:24]
of the first Dword of the table entry (where the byte count
is located) will be loaded directly into
DMA Next Address
64 (DNAD64) to provide a 40-bit address.
The format for the table indirect entries for each mode is
shown below. The table for Table Indirect block moves
upper 32-bit address locations summarizes the available
modes for table indirect block moves.
Index Mode 0 (64TIMOD clear) table entry format:
Index Mode 1 (64TIMOD set) table entry format:
Table Indirect block moves upper 32-bit address
locations:
31 29 28 24 23 0
R Sel Index Byte Count
Source/Destination Address [31:0]
31 24 23 0
Src/Dest Addr [39:32] Byte Count
Source/Destination Address [31:0]
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