Datasheet

 2010-2013 Microchip Technology Inc. DS40001430E-page 91
PIC16(L)F720/721
12.2 Option Register
REGISTER 12-1: OPTION_REG: OPTION REGISTER
R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1
RABPU 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 RABPU
: PORTA or PORTB Pull-up Enable bit
1 = PORTA or PORTB pull-ups are disabled
0 = PORTA or PORTB pull-ups are enabled by individual PORT latch values
bit 6 INTEDG: Interrupt Edge Select bit
1 = Interrupt on rising edge of INT pin
0 = Interrupt on falling edge of INT pin
bit 5 T0CS: TMR0 Clock Source Select bit
1 = Transition on T0CKI pin
0 = Internal instruction cycle clock (F
OSC/4)
bit 4 T0SE: TMR0 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 is assigned to the WDT
0 = Prescaler is assigned to the Timer0 module
bit 2-0 PS<2:0>: Prescaler Rate Select bits
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
Bit Value TMR0 Rate WDT R
ate
TABLE 12-1: SUMMARY OF REGISTERS ASSOCIATED WITH TIMER0
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Register
on Page
INTCON GIE PEIE TMR0IE INTE RABIE TMR0IF INTF RABIF 38
OPTION_REG
RABPU INTEDG T0CS T0SE PSA PS2 PS1 PS0 21
TMR0 Timer0 module Register 89
TRISA
— — TRISA5 TRISA4 — TRISA2 TRISA1 TRISA0 46
Legend: – = Unimplemented locations, read as ‘0’, u = unchanged, x = unknown. Shaded cells are not used by the
Timer0 module.