6 transfer control instructions, Transfer control instructions – LSI 53C875A User Manual

Page 225

Advertising
background image

Transfer Control Instructions

5-25

Miscellaneous Notes:

• Substitute the desired register name or address for “RegA” in the syntax examples.
• data8 indicates eight bits of data.
• Use SFBR instead of data8 to add two register values.

5.6 Transfer Control Instructions

This section describes the Transfer Control Instructions. The
configuration of the OpCode bits define which Transfer Control Instruction
to perform.

100

AND data with register and
place the result in the same
register. Syntax: “Move
RegA & data8 to RegA”

AND data with register and
place the result in the

SCSI

First Byte Received (SFBR)

register. Syntax: “Move
RegA & data8 to SFBR”

AND data with SFBR and
place the result in the
register. Syntax: “Move
SFBR & data8 to RegA”

101

1

Shift register one bit to the
right and place the result in
the same register. Syntax:
“Move RegA SHR RegA”

Shift register one bit to the
right and place the result in
the

SCSI First Byte

Received (SFBR)

register.

Syntax: “Move RegA SHR
SFBR”

Shift the SFBR register one
bit to the right and place the
result in the register. Syntax:
“Move SFBR SHR RegA”

110

Add data to register without
carry and place the result
in the same register.
Syntax: “Move RegA +
data8 to RegA”

Add data to register without
carry and place the result in
the

SCSI First Byte

Received (SFBR)

register.

Syntax: “Move RegA + data8
to SFBR”

Add data to SFBR without
carry and place the result in
the register. Syntax: “Move
SFBR + data8 to RegA”

111

Add data to register with
carry and place the result
in the same register.
Syntax: “Move RegA +
data8 to RegA with carry”

Add data to register with
carry and place the result in
the

SCSI First Byte

Received (SFBR)

register.

Syntax: “Move RegA + data8
to SFBR with carry”

Add data to SFBR with carry
and place the result in the
register. Syntax: “Move
SFBR + data8 to RegA with
carry”

1. Data is shifted through the Carry bit and the Carry bit is shifted into the data byte.

Table 5.3

Read/Write Instructions (Cont.)

Operator

OpCode 111
Read-Modify-Write

OpCode 110
Move to SFBR

OpCode 101
Move from SFBR

Advertising