beautypg.com

5 transfer control instructions, 1 first dword, Transfer control instructions – Avago Technologies LSI53C1000R User Manual

Page 269: First dword, Transfer control instructions – first dword, Section 5.5, “transfer control instructions

background image

Transfer Control Instructions

5-27

Version 2.2

Copyright © 2000–2003 by LSI Logic Corporation. All rights reserved.

5.5 Transfer Control Instructions

This section describes transfer control instructions for the first Dword,
second Dword, and third Dword.

5.5.1 First Dword

This section describes the first Dword of the Transfer Control Instruction
register.

Figure 5.9

Transfer Control Instructions – First Dword

IT[1:0]

Instruction Type –
Transfer Control Instruction

[31:30]

OPC[2:0]

Opcode

[29:27]

This 3-bit field specifies the type of transfer control
instruction to execute. All transfer control instructions can
be conditional. They can be dependent on a true/false
comparison of the ALU Carry bit, or a comparison of the
SCSI information transfer phase with the Phase field,
and/or a comparison of the First Byte Received with the
Data Compare field. Each instruction can operate in the
initiator or target mode.

Jump Instruction

The LSI53C1000R can do a true/false comparison of the
ALU carry bit, or compare the phase and/or data as
defined by the Phase Compare, Data Compare and
True/False bit fields. If the comparisons are true, it loads

31 30 29

27 26

24 23 22 21 20 19 18 17 16 15

8

7

0

DCMD Register

DBC Register

IT[1:0] OPC[2:0] SCSIP[2:0] RA J CT IF TF CD CP VP

MC

DC

OPC2

OPC1

OPC0 Instruction Defined

0

0

0

Jump

0

0

1

Call

0

1

0

Return

0

1

1

Interrupt

1

x

x

Reserved

This manual is related to the following products: