LSI53C875 LSI Logic, LSI53C875 Datasheet - Page 220

• Manufacturer Part Number: LSI53C875
• Description: PCI to Ultra SCSI I/O Processor
• Manufacturer: LSI Logic

6.4.4 Move To/From SFBR Cycles
Table 6.2
6-24
Operator
000
001
010
011
1
Opcode 111
Read-Modify-Write
Move data into register.
Syntax: “Move data8 to
RegA”
Shift register one bit to the
left and place the result in
the same register. Syntax:
“Move RegA SHL RegA”
OR data with register and
place the result in the same
register. Syntax: “Move
RegA | data8 to RegA”
XOR data with register and
place the result in the same
register. Syntax: “Move
RegA XOR data8 to RegA”
Read/Write Instructions
All operations are read-modify-writes. However, two registers are
involved, one of which is always the SFBR.
read-modify-write operations. The possible functions of this instruction
are:
Instruction Set of the I/O Processor
Write one byte (value contained within the SCRIPTS instruction) into
any chip register.
Move to/from the SFBR from/to any other register.
Alter the value of a register with AND, OR, ADD, XOR, SHIFT LEFT,
or SHIFT RIGHT operators.
After moving values to the SFBR, the compare and jump, call, or
similar instructions are used to check the value.
A Move-to-SFBR followed by a Move-from-SFBR is used to perform
a register-to-register move.
Opcode 110
Move to SFBR
Move data into
Byte Received (SFBR)
register. Syntax: “Move
data8 to SFBR”
Shift register one bit to the
left and place the result in
the
Received (SFBR)
Syntax: “Move RegA SHL
SFBR”
OR data with register and
place the result in the
First Byte Received (SFBR)
register. Syntax: “Move
RegA | data8 to SFBR”
XOR data with register and
place the result in the
First Byte Received (SFBR)
register. Syntax: “Move
RegA XOR data8 to SFBR”
SCSI First Byte
SCSI First
register.
SCSI
SCSI
Table 6.2
Opcode 101
Move from SFBR
Move data into register.
Syntax: “Move data8 to
RegA”
Shift the
Received (SFBR)
one bit to the left and place
the result in the register.
Syntax: “Move SFBR SHL
RegA”
OR data with SFBR and
place the result in the
register. Syntax: “Move
SFBR | data8 to RegA”
XOR data with SFBR and
place the result in the
register. Syntax: “Move
SFBR XOR data8 to RegA”
shows the possible
SCSI First Byte
register