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Avago Technologies LSI53C1010 User Manual

Page 64

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3-24

The SCSI SCRIPTS Processor Instruction Set

Register
Definition(s)

The information listed below describes the DBC and DSPS registers.

COMMAND

0

1

0

STATUS

0

1

1

RES4

4

(DT_DATA_OUT)

3

1

0

0

RES5

4

(DT_DATA_IN

)3

1

0

1

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 3.7

SCSI Phase Bit Values (INTFLY Format)

1

(Cont.)

Phase

Message

Command/Data

Input/Output

Carry Test

When this bit is set, true/false comparisons may be made
based on the ALU Carry bit. Carry comparisons cannot be
made in the same instruction as data or phase comparisons.

Int on Fly

When this bit is set, the Interrupt instruction will not halt the
SCRIPTS processor.

True

Transfer on TRUE/FALSE condition.
0 - Transfer if condition is FALSE
1 - Transfer if condition is TRUE

Compare
Data

Compare data byte to first byte of the received data.
0 - Do not compare data
1 - Perform comparison

Compare
Phase

Compare current SCSI phase to SCSI phase field or SATN.
This bit is set whenever the Phase operand is used.
0 - Do not compare phase
1 - Perform comparison

Wait

Wait for valid phase. This bit is set by the WHEN operand in
the instruction, and cleared by the IF operand.
0 - Perform comparison immediately
1 - Wait for valid phase (SREQ/ asserted by target)

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