AT&T 3B2/300 Technical Reference Manual page 313

FUNCTIONAL D E S C R I P T I O N - - - - - - - - - - - - - - - - - - - - - - - - - - -
Command Register
The Command Register (CR) stores command words used to initiate MAU operations. The format
of this 32-bit register is as follows.
COMMAND REGISTER
BITS 31 - 24 23 - 15 14 - 10 09 - 07 06 - 04 03 - 00
FIELD ID UNUSED OPCODE OPl OP2 OP3
The CR fields are defined in the following paragraphs.
ID
UNUSED
OPCODE
Bits 31-24 are the Processor Identification Number of the processor that should
react to the command word. The MAU is ID 0.
Bits 23-15 are not used. These bits are returned as zeros for a read operation.
Bits 14-10 are the Operation Code (OPCODE) field. The OPCODE field specifies
the operation to be done. The OPCODES are as follows.
OPCODE MNEMONIC INSTRUCTION
Ox 02 ADD ADD
Ox 03 SUB SUBTRACT
Ox 04 DIV DIVIDE
Ox 05
REM REMAINDER
Ox 06
MUL MULTIPLY
Ox 07 MOVE MOVE
Ox 08
RDASR MOVE FROM ASR
Ox 09
WRASR MOVE TO ASR
Ox OA CMP COMPARE
Ox OB
CMPE COMP ARE WITH EXCEPTIONS
Ox OC
ABS ABSOLUTE VALUE
Ox OD SQRT SQUARE ROOT
Ox OE
RTOI ROUND TO INTEGRAL VALUE
Ox OF
FTOI CONVERT FLOATING POINT TO INTEGER
Ox 10 JTOF CONVERT INTEGER TO FLOATING POINT
Ox 11 DTOF
CONVERT DECIMAL TO FLOATING POINT
Ox 12 FTOD CONVERT FLOATING POINT TO DECIMAL
Ox 13
NOP NO OPERATION
Ox 14 EROF EXTRACT RESULT ON FAULT
Ox 17 NEG NEGATE
Ox 18
LOR LOAD DAT A REGISTER
Ox IA CMPS COMPARE WITH FLAGS SWAPPED
Ox 1B CMPS
COMPARE WITH EXCEPTIONS AND FLAGS SWAPPED
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