PIC16HV540 Microchip Technology, PIC16HV540 Datasheet - Page 14

• Manufacturer Part Number: PIC16HV540
• Description: Enhanced PIC16C54 EPROM-Based 8-Bit CMOS Microcontroller
• Manufacturer: Microchip Technology

PIC16HV540
4.4
The OPTION register is a 6-bit wide, write-only register
which contains various control bits to configure the
Timer0/WDT prescaler and Timer0.
EXAMPLE 4-1:
movlw
OPTION
REGISTER 4-2: OPTION REGISTER
DS40197B-page 14
bit7
bit 7-6:
bit 5:
bit 4:
bit 3:
bit 2-0:
U-0
—
OPTION Register
‘0000 0111’b
Unimplemented
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
Bit Value
U-0
000
001
010
011
100
101
110
111
—
INSTRUCTIONS FOR INITIALIZING OPTION REGISTER
T0CS
Timer0 Rate WDT Rate
W-1
1 : 2
1 : 4
1 : 8
1 : 16
1 : 32
1 : 64
1 : 128
1 : 256
; load OPTION setup value into W
; initialize OPTION register
T0SE
W-1
1 : 1
1 : 2
1 : 4
1 : 8
1 : 16
1 : 32
1 : 64
1 : 128
PSA
W-1
Preliminary
W-1
PS2
By executing the OPTION instruction, the contents of
the W register will be transferred to the OPTION regis-
ter. A RESET sets the OPTION<5:0> bits.
Example 4-1 illustrates how to initialize the OPTION
register.
PS1
W-1
W-1
PS0
0
U = Unimplemented bit
- n = Value at POR reset
W = Writable bit
2000 Microchip Technology Inc.