PIC12F635/PIC16F636/639
REGISTER 4-3:
WDA: WEAK PULL-UP/PULL-DOWN DIRECTION REGISTER
U-0
—
U-0
—
R/W-1
WDA5
R/W-1
WDA4
U-0
—
R/W-1
WDA2
R/W-1
WDA1
R/W-1
WDA0
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7-6
bit 5-4
Unimplemented: Read as ‘0’
WDA<5:4>: Pull-up/Pull-down Selection bits
1= Pull-up selected
0= Pull-down selected
bit 3
Unimplemented: Read as ‘0’
bit 2-0
WDA<2:0>: Pull-up/Pull-down Selection bits
1= Pull-up selected
0= Pull-down selected
Note 1: The weak pull-up/pull-down device is enabled only when the global RAPU bit is enabled, the pin is in Input mode (TRIS
= 1), the individual WDA bit is enabled (WDA = 1) and the pin is not configured as an analog input or clock function.
2: RA3 pull-up is enabled when the pin is configured as MCLR in the Configuration Word register and the device is not in
Programming mode.
REGISTER 4-4:
WPUDA: WEAK PULL-UP/PULL-DOWN ENABLE REGISTER
U-0
—
U-0
—
R/W-1
R/W-1
U-0
—
R/W-1
R/W-1
R/W-1
(3)
(3)
WPUDA5
WPUDA4
WPUDA2
WPUDA1
WPUDA0
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
x = Bit is unknown
bit 7-6
bit 5-4
Unimplemented: Read as ‘0’
(3)
WPUDA<5:4>: Pull-up/Pull-down Direction Selection bits
1= Pull-up/pull-down enabled
0= Pull-up/pull-down disabled
bit 3
Unimplemented: Read as ‘0’
bit 2-0
WPUDA<2:0>: Pull-up/Pull-down Direction Selection bits
1= Pull-up/pull-down enabled
0= Pull-up/pull-down disabled
Note 1: The weak pull-up/pull-down direction device is enabled only when the global RAPU bit is enabled, the pin is in Input mode
(TRIS = 1), the individual WPUDA bit is enabled (WPUDA = 1) and the pin is not configured as an analog input or clock
function.
2: RA3 pull-up is enabled when the pin is configured as MCLR in the Configuration Word register and the device is not in
Programming mode.
3: WPUDA5 bit can be written if INTOSC is enabled and T1OSC is disabled; otherwise, the bit can not be written and reads
as ‘1’. WPUDA4 bit can be written if not configured as OSC2; otherwise, the bit can not be written and reads as ‘1’
© 2007 Microchip Technology Inc.
DS41232D-page 49
MICROCHIP [ MICROCHIP ]
