PIC18F242 MICROCHIP [Microchip Technology], PIC18F242 Datasheet - Page 105

• Manufacturer Part Number: PIC18F242
• Description: 28/40-pin High Performance, Enhanced FLASH Microcontrollers with 10-Bit A/D
• Manufacturer: MICROCHIP [Microchip Technology]

10.0
The Timer0 module has the following features:
• Software selectable as an 8-bit or 16-bit timer/
• Readable and writable
• Dedicated 8-bit software programmable prescaler
• Clock source selectable to be external or internal
• Interrupt-on-overflow from FFh to 00h in 8-bit
• Edge select for external clock
REGISTER 10-1:
© 2006 Microchip Technology Inc.
counter
mode and FFFFh to 0000h in 16-bit mode
TIMER0 MODULE
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2-0
T0CON: TIMER0 CONTROL REGISTER
Legend:
R = Readable bit
- n = Value at POR
bit 7
TMR0ON: Timer0 On/Off Control bit
1 = Enables Timer0
0 = Stops Timer0
T08BIT: Timer0 8-bit/16-bit Control bit
1 = Timer0 is configured as an 8-bit timer/counter
0 = Timer0 is configured as a 16-bit timer/counter
T0CS: Timer0 Clock Source Select bit
1 = Transition on T0CKI pin
0 = Internal instruction cycle clock (CLKO)
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: Timer0 Prescaler Assignment bit
1 = TImer0 prescaler is NOT assigned. Timer0 clock input bypasses prescaler.
0 = Timer0 prescaler is assigned. Timer0 clock input comes from prescaler output.
T0PS2:T0PS0: Timer0 Prescaler Select bits
111 = 1:256 prescale value
110 = 1:128 prescale value
101 = 1:64 prescale value
100 = 1:32 prescale value
011 = 1:16 prescale value
010 = 1:8 prescale value
001 = 1:4 prescale value
000 = 1:2 prescale value
TMR0ON
R/W-1
T08BIT
R/W-1
R/W-1
W = Writable bit
T0CS
’1’ = Bit is set
Figure 10-1 shows a simplified block diagram of the
Timer0 module in 8-bit mode and Figure 10-2 shows a
simplified block diagram of the Timer0 module in 16-bit
mode.
The T0CON register (Register 10-1) is a readable and
writable register that controls all the aspects of Timer0,
including the prescale selection.
R/W-1
T0SE
U = Unimplemented bit, read as ‘0’
’0’ = Bit is cleared
R/W-1
PSA
T0PS2
R/W-1
PIC18FXX2
x = Bit is unknown
T0PS1
R/W-1
DS39564C-page 103
T0PS0
R/W-1
bit 0