PIC16F5X
3.4
Option Register
The Option register is a 6-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<5:0> bits.
REGISTER 3-2:
OPTION REGISTER
U-0
—
U-0
—
W-1
W-1
W-1
PSA
W-1
PS2
W-1
PS1
W-1
PS0
T0CS
T0SE
bit 7
bit 0
bit 7-6
bit 5
Unimplemented: Read as ‘0’
T0CS: Timer0 Clock Source Select bit
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
Bit Value
Timer0 Rate WDT Rate
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
Legend:
R = Readable bit
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
- n = Value at POR
DS41213D-page 18
© 2007 Microchip Technology Inc.