PIC16F57 Microchip Technology Inc., PIC16F57 Datasheet - Page 20

• Manufacturer Part Number: PIC16F57
• Description: Flash-based, 8-bit Cmos Microcontroller Series
• Manufacturer: Microchip Technology Inc.

PIC16F5X
3.4
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:
DS41213D-page 18
Option Register
bit 7-6
bit 5
bit 4
bit 3
bit 2-0
Unimplemented: Read as ‘0’
T0CS: Timer0 Clock Source Select bit
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
Legend:
R = Readable bit
- n = Value at POR
OPTION REGISTER
bit 7
U-0
—
Bit Value
000
001
010
011
100
101
110
111
U-0
—
Timer0 Rate
1 : 2
1 : 4
1 : 8
1 : 16
1 : 32
1 : 64
1 : 128
1 : 256
T0CS
W-1
W = Writable bit
‘1’ = Bit is set
WDT Rate
1 : 1
1 : 2
1 : 4
1 : 8
1 : 16
1 : 32
1 : 64
1 : 128
T0SE
W-1
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
PSA
W-1
PS2
W-1
© 2007 Microchip Technology Inc.
x = Bit is unknown
PS1
W-1
PS0
W-1
bit 0