Datasheet

 2010 Microchip Technology Inc. DS41326E-page 19
PIC16F526
4.4 OPTION Register
The OPTION register is a 8-bit wide, write-only register,
which contains various control bits to configure the
Timer0/WDT prescaler and Timer0.
By executing the OPTION instruction, the contents of
the W register will be transferred to the OPTION
register. A Reset sets the OPTION <7:0> bits.
Note: If TRIS bit is set to ‘0’, the wake-up on
change and pull-up functions are disabled
for that pin (i.e., note that TRIS overrides
Option control of RBPU
and RBWU).
REGISTER 4-2: OPTION: OPTION REGISTER
W-1 W-1 W-1 W-1 W-1 W-1 W-1 W-1
RBWU
RBPU T0CS
(1)
T0SE PSA PS2 PS1 PS0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 RBWU
: Enable Wake-up On Pin Change bit (RB0, RB1, RB3, RB4)
1 = Disabled
0 = Enabled
bit 6 RBPU
: Enable Weak Pull-ups bit (RB0, RB1, RB3, RB4)
1 = Disabled
0 = Enabled
bit 5 T0CS: Timer0 Clock Source Select bit
(1)
1 = Transition on T0CKI pin
0 = Internal instruction cycle clock (CLKOUT)
bit 4 T0SE: Timer0 Source Edge Select bit
1 = Increment on high-to-low transition on T0CKI pin
0 = Increment on low-to-high transition on T0CKI pin
bit 3 PSA: Prescaler Assignment bit
1 = Prescaler assigned to the WDT
0 = Prescaler assigned to Timer0
bit 2-0 PS<2:0>: Prescaler Rate Select bits
Note 1: If the T0CS bit is set to ‘1’, it will override the TRIS function on the T0CKI pin.
000
001
010
011
100
101
110
111
1 : 2
1 : 4
1 : 8
1 : 16
1 : 32
1 : 64
1 : 128
1 : 256
1 : 1
1 : 2
1 : 4
1 : 8
1 : 16
1 : 32
1 : 64
1 : 128
Bit Value Timer0 Rate WDT Rate