gc80c520g CORERIVER Semiconductor, gc80c520g Datasheet - Page 23

• Manufacturer Part Number: gc80c520g
• Description: Eprom / Rom / Romless Based 8-bit Turbo Microcontrollers
• Manufacturer: CORERIVER Semiconductor

P4SEL (A6h) : P4 Pull-up Control Register
P4 (A5h) : PORT4 Register
6.5. I/O Ports : PORT4[3:0]
Quasi bi-directional port.
Pull-up resistors are switched on/off by changing the value of the P4SEF SFR.
Available only for 44-pin PLCC package
Read-Modify-Write instructions do not read port pin but the port SFR.
PORT4 Description
-
-
P4SEL[3:0] :
ANL
-
-
/
ORL
Pull-up resistor Enable
0 = Pull-up resistor ON / 1 = Pull-up resistor Off
PORT4 Pull-up resistor is
-
-
/
XRL
/
-
-
JBC
P4SEL.3 P4SEL.2 P4SEL.1 P4SEL.0
/
R/W(0) R/W(0) R/W(0) R/W(0)
R/W(1) R/W(1) R/W(1) R/W(1)
P4.3
CPL
/
INC
P4.2
ON
/
after reset.
DEC
P4.1
/
DJNZ
P4.0
CPU BUS
P4.0
SFR
Digital Input
QB
Q
2 OSC
Pulse
MiDAS1.0 Family
Pull-
up
P4SEL.0
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