PIC16F526 Datasheet, PDF (19/122 Pages) Microchip Technology – 14-Pin, 8-Bit Flash Microcontroller

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.
REGISTER 4-2: OPTION: OPTION REGISTER
W-1
RBWU
bit 7
W-1
RBPU
W-1
T0CS⁽¹⁾
W-1
T0SE
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).
W-1
W-1
PSA
PS2
W-1
W-1
PS1
PS0
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
bit 6
bit 5
bit 4
bit 3
bit 2-0
RBWU: Enable Wake-up On Pin Change bit (RB0, RB1, RB3, RB4)
1 = Disabled
0 = Enabled
RBPU: Enable Weak Pull-ups bit (RB0, RB1, RB3, RB4)
1 = Disabled
0 = Enabled
T0CS: Timer0 Clock Source Select bit⁽¹⁾
1 = Transition on T0CKI pin
0 = Internal instruction cycle clock (CLKOUT)
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
PSA: Prescaler Assignment bit
1 = Prescaler assigned to the WDT
0 = Prescaler assigned to Timer0
PS<2:0>: Prescaler Rate Select bits
Bit Value Timer0 Rate WDT Rate
000
1:2
1:1
001
1:4
1:2
010
1:8
1:4
011
1 : 16
1:8
100
1 : 32
1 : 16
101
1 : 64
1 : 32
110
1 : 128
1 : 64
111
1 : 256
1 : 128
Note 1: If the T0CS bit is set to ‘1’, it will override the TRIS function on the T0CKI pin.
 2010 Microchip Technology Inc.
DS41326D-page 19