Datasheet

ManualsBrandsMICROCHIP TECHNOLOGY ManualsMicrocontrollers, Microprocessors & QuartzesEmbedded microcontroller SSOP 20 8-Bit 20 MHz I/O number 17

PIC16F785/HV785

2.2.2.2 OPTION_REG Register

The Option register is a readable and writable register,

which contains various control bits to configure the

TMR0/WDT prescaler, the external RA2/INT interrupt,

the TMR0 and the weak pull-ups on PORTA.

Note: To achieve a 1:1 prescaler assignment for

TMR0, assign the prescaler to the WDT by

setting PSA bit to ‘1’ in the OPTION Reg-

ister. See Section 5.4 “Prescaler”.

R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1

RAPU

INTEDG T0CS 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 RAPU

: PORTA Pull-up Enable bit

1 = PORTA pull-ups are disabled

0 = PORTA pull-ups are enabled by individual port latch values in WPUA register

bit 6 INTEDG: Interrupt Edge Select bit

1 = Interrupt on rising edge of RA2/AN2/T0CKI/INT/C1OUT pin

0 = Interrupt on falling edge of RA2/AN2/T0CKI/INT/C1OUT pin

bit 5 T0CS: TMR0 Clock Source Select bit

1 = Transition on RA2/AN2/T0CKI/INT/C1OUT pin

0 = Internal instruction cycle clock (CLKOUT)

bit 4 T0SE: TMR0 Source Edge Select bit

1 = Increment on high-to-low transition on RA2/AN2/T0CKI/INT/C1OUT pin

0 = Increment on low-to-high transition on RA2/AN2/T0CKI/INT/C1OUT pin

bit 3 PSA: Prescaler Assignment bit

1 = Prescaler is assigned to the WDT

0 = Prescaler is assigned to the Timer0 module

bit 2-0 PS<2:0>: Prescaler Rate Select bits

Note 1: A dedicated 16-bit WDT postscaler is available for the PIC16F785/HV785.

See Section 15.5 “Watchdog Timer (WDT)” for more information.

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