LSI 53C810A User Manual
Read/Write Instructions
6-23
6.5 Read/Write Instructions
The Read/Write instruction type moves the contents of one register to
another, or performs arithmetic operations such as AND, OR, XOR,
Addition, and Shift.
another, or performs arithmetic operations such as AND, OR, XOR,
Addition, and Shift.
6.5.1 First Dword
IT[1:0]
Instruction Type - Read/Write Instruction
[31:30]
The Read/Write instruction uses operator bits 26 through
24 in conjunction with the opcode bits to determine which
instruction is currently selected.
24 in conjunction with the opcode bits to determine which
instruction is currently selected.
OPC[2:0]
OpCode
[29:27]
The combinations of these bits determine if the
instruction is a Read/Write or an I/O instruction. Opcodes
0b000 through 0b100 are considered I/O instructions.
Refer to
instruction is a Read/Write or an I/O instruction. Opcodes
0b000 through 0b100 are considered I/O instructions.
Refer to
for field definitions.
O[2:0]
Operator
[26:24]
These bits are used in conjunction with the opcode bits
to determine which instruction is currently selected. Refer
to
to determine which instruction is currently selected. Refer
to
for field definitions.
A[6:0]
Register Address - A[6:0]
[22:16]
It is possible to change register values from SCRIPTS in
read-modify-write cycles or move to/from SFBR cycles.
A[6:0] select an 8-bit source/destination register within
the LSI53C810A.
read-modify-write cycles or move to/from SFBR cycles.
A[6:0] select an 8-bit source/destination register within
the LSI53C810A.
6.5.2 Second Dword
Destination Address
[31:0]
This field contains the 32-bit destination address where
the data is to move.
the data is to move.
6.5.3 Read-Modify-Write Cycles
During these cycles the register is read, the selected operation is
performed, and the result is written back to the source register.
performed, and the result is written back to the source register.