Port 9 - NEC V850E/MS1 UPD703100 User Manual

12.3.10 Port 9

Port 9 is an 8-bit input/output port that can be set to input or output in 1-bit units.
7 6
P9 P97 P96
Bit Position Bit Name
7 to 0 P9n (n = 7 to 0)
In addition to their function as port pins, the port 9 pins can also operate in the control mode (external expansion
mode) as control signal outputs and bus hold control signal output used when memory is expanded externally.
(1) Operation in control mode
Port
Port 9 P90 LWR/LCAS
P91 UWR/UCAS
P92 RD
P93 WE
P94 BCYST
P95 OE
P96 HLDAK
P97 HLDRQ
CHAPTER 12 PORT FUNCTIONS
5 4 3
P95 P94 P93
Port 9
Input/output port
Control Mode
Control signal output in memory
expansion
Bus hold acknowledge signal output
Bus hold request signal input
User's Manual U12688EJ4V0UM00
2 1 0
P92 P91 P90
Function
Remark
Address After reset
FFFFF012H Undefined
Block Type
O
H
391