
2009 Microchip Technology Inc.
DS41341E-page 113
PIC16F72X/PIC16LF72X
TABLE 11-1:
SUMMARY OF REGISTERS ASSOCIATED WITH TIMER0
REGISTER 11-1:
OPTION_REG: OPTION REGISTER
R/W-1
RBPU
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
RBPU: PORTB Pull-up Enable bit
1
= PORTB pull-ups are disabled
0
= 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 or CPSOSC signal
0
= Internal instruction cycle clock (FOSC/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 RATE
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR, BOR
Value on
all other
Resets
CPSCON0
CPSON
—
CPSRNG1 CPSRNG0
CPSOUT
T0XCS
0--- 0000
INTCON
GIE
PEIE
T0IE
INTE
RBIE
T0IF
INTF
RBIF
0000 000x
OPTION_REG
RBPU
INTEDG
T0CS
T0SE
PSA
PS2
PS1
PS0
1111 1111
TMR0
Timer0 Module Register
xxxx xxxx
uuuu uuuu
TRISA
TRISA7
TRISA6
TRISA5
TRISA4
TRISA3
TRISA2
TRISA1
TRISA0
1111 1111
Legend:
– = Unimplemented locations, read as ‘0’, u = unchanged, x = unknown. Shaded cells are not used by the Timer0 module.