Coprocessor Instruction Types - Motorola MC68020 User Manual

CPU SPACE ADDRESS
Figure 7-4. Coprocessor Address Map in MC68020/EC020 CPU Space
31
$00
$04
$08
$0C
$10
$14
$18
$1C
Figure 7-5. Coprocessor Interface Register Set Map

7.2 COPROCESSOR INSTRUCTION TYPES

The M68000 coprocessor interface supports four categories of coprocessor instructions:
general, conditional, context save, and context restore. The category name indicates the
type of operations provided by the coprocessor instructions in the category. The
instruction category also determines the CIR accessed by the MC68020/EC020 to initiate
instruction and communication protocols between the main processor and the
coprocessor necessary for instruction execution.
During the execution of instructions in the general or conditional categories, the
coprocessor uses the set of coprocessor response primitive codes defined for the M68000
coprocessor interface to request services from and indicate status to the main processor.
During the execution of the instructions in the context save and context
MOTOROLA
$20000
INTERFACE REGISTER SET
$2001F
RESERVED
$22000
INTERFACE REGISTER SET
$2201F
RESERVED
$24000
$2E000
INTERFACE REGISTER SET
$2E01F
RESERVED
RESPONSE
SAVE
OPERATION WORD
(RESERVED)
REGISTER SELECT
INSTRUCTION ADDRESS
OPERAND ADDRESS
M68020 USER'S MANUAL
ADDRESS SPACE FOR
COPROCESSOR WITH
CpID = 0
ADDRESS SPACE FOR
COPROCESSOR WITH
CpID = 1
ADDRESS SPACE FOR
COPROCESSOR WITH
CpID = 7
16 15
CONTROL
RESTORE
COMMAND
CONDITION
OPERAND
(RESERVED)
0
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