Avago Technologies LSI53C1010 - Manual (Page 85)

Instruction Descriptions 3-45
Register
Definition(s) The information listed below describes the DBC and DSPS registers.
Description There are various forms of the Block Move instruction. The “address” and
“count” terms specify the address and byte count fields of the instruction.
If the optional keyword “PTR” is present the Indirect bit is set. If the
optional keyword FROM is present the Table Indirect bit is set (for more
information on Table Indirect addressing, refer to
Chapter 9 ). PTR and
FROM may not be used in the same instruction. “Phase” specifies the
phase field of the instruction. WITH or WHEN are used to specify the
Block Move function codes. WITH is used to signal the target role which
sets the phase values, and WHEN is the initiator “test for phase” feature.
The SCRIPTS processor waits for a valid phase (initiator) or drives the
phase lines (target). In the initiator role, it performs a comparison looking
for a match between the phase specified in the SCRIPT and the actual
value on the bus. If the phases do not match, a phase mismatch interrupt
occurs. If the phases match, data is transferred in or out according to the
phase lines. After the last byte is transferred to its final destination, the
SCRIPTS processor fetches the next SCRIPTS instruction. If the target
changes phase in the middle of a block move, a phase mismatch
interrupt will occur.
Notes In the target mode, a MOVE instruction with a byte count of zero can be
used during a Command phase. The SCRIPTS processor will determine
the number of bytes to move from the command group code in the first
byte of the command.
MESSAGE_OUT 1 1 0
MESSAGE_IN 1 1 1
1. 0 - False, negated; 1 - True, asserted. For these phases, SEL is negated and
BSY is asserted.
2. All chips except LSI53C10XX.
3. LSI53C10XX chips.
4. RES4 and RES5 are reserved SCSI phases except in the LSI53C10XX chips.
Table 3.13 SCSI Phase Bit Values (MOVE Format)
1
Phase Message Command/Data Input/Output
Byte Count A 24-bit number indicating the number of bytes to transfer.
Dest Addr Destination address for the transfer.