msm80c86a-10js Oki Semiconductor, msm80c86a-10js Datasheet - Page 17

• Manufacturer Part Number: msm80c86a-10js
• Description: 16-bit Cmos Microprocessor
• Manufacturer: Oki Semiconductor

The following pin function descriptions are minimum mode only. Other pin functions are
M/IO
STATUS: Output
WR
WRITE: Output
¡ Semiconductor
RQ/GT
RQ/GT
REQUEST/GRANT:Input/Output
LOCK
LOCK:Output
QS
QUEUE STATUS: Output
already described.
These lines are used for Bus Request from other devices and Bus GRANT to other devices.
These lines are bidirectional and active low.
This line is active low.
When this line is low, other devices cannot gain control of the bus.
This line is high impedance during hold acknowledge.
These lines are Queue Status, and indicate internal instruction queue status.
This line selects memory address space or I/O address space.
When this line is high, the CPU selects memory address space and when it is low, the CPU
selects I/O address space.
This line is high impedance during hold acknowledge.
This line indicates that the CPU is in the memory or I/O write cycle.
This line is a write strobe signal when the CPU writes data to memory of I/O device.
This line is active low.
This line is high impedance during hold acknowledge.
0
0 (LOW)
0
1 (HIGH)
1
/QS
0 (LOW)
1 (HIGH)
QS1
S
0
1
0
0
0
1
1
1
1
2
QS0
0
1
0
1
S
0
0
1
1
0
0
1
1
1
No operation
First Byte of Op Code from Queue
Empty the Queue
Subsequent Byte from Queue
S
0
1
0
1
0
1
0
1
0
Characteristics
Interrupt acknowledge
Read I/O Port
Write I/O Port
Halt
Code Access
Read Memory
Write Memory
Passive
Characteristics
MSM80C86A-10RS/GS/JS
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