SN8P2501D
8-Bit Micro-Controller
SONiX TECHNOLOGY CO., LTD
Page 63
Version 1.5
7.3 I/O PULL UP REGISTER
The I/O pins build in internal pull-up resistors and only support I/O input mode. The port internal pull-up resistor is
programmed by PnUR register. When the bit of PnUR register is
“0”, the I/O pin’s pull-up is disabled. When the bit of
PnUR register is
“1”, the I/O pin’s pull-up is enabled.
0E0H
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
P0UR
-
-
-
-
-
-
-
P00R
Read/Write
-
-
-
-
-
-
-
W
After reset
-
-
-
-
-
-
-
0
0E1H
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
P1UR
-
-
-
-
P13R
P12R
-
P10R
Read/Write
-
-
-
-
W
W
-
W
After reset
-
-
-
-
0
0
-
0
0E2H
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
P2UR
-
-
P25R
P24R
P23R
P22R
P21R
P20R
Read/Write
-
-
W
W
W
W
W
W
After reset
-
-
0
0
0
0
0
0
0E5H
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
P5UR
-
-
-
P54R
-
-
-
-
Read/Write
-
-
-
W
-
-
-
-
After reset
-
-
-
0
-
-
-
-
Note: P1.1 is input only pin and without pull-up resister. The P1UR.1 is undefined.
Example: I/O Pull up Register
MOV
A, #0FFH
; Enable Port0, 2, 5 Pull-up register,
B0MOV
P0UR, A
;
B0MOV
P2UR,A
B0MOV
P5UR, A