![](http://datasheet.mmic.net.cn/Microchip-Technology/PIC16C57-HSI-P_datasheet_99429/PIC16C57-HSI-P_40.png)
PIC16C5X
DS30453D-page 38
Preliminary
2002 Microchip Technology Inc.
FIGURE 8-3:
TIMER0 TIMING: INTERNAL CLOCK/NO PRESCALER
FIGURE 8-4:
TIMER0 TIMING: INTERNAL CLOCK/PRESCALER 1:2
TABLE 8-1:
REGISTERS ASSOCIATED WITH TIMER0
Address
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
Power-on
Reset
Value on
MCLR and
WDT Reset
01h
TMR0
Timer0 - 8-bit real-time clock/counter
xxxx xxxx
uuuu uuuu
N/A
OPTION
—
T0CS
T0SE
PSA
PS2
PS1
PS0
--11 1111
Legend: x = unknown, u = unchanged, - = unimplemented. Shaded cells not used by Timer0.
PC-1
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
PC
(Program
Counter)
Instruction
Fetch
Timer0
PC
PC+1
PC+2
PC+3
PC+4
PC+5
PC+6
T0
T0+1
T0+2
NT0
NT0+1
NT0+2
MOVWF TMR0
MOVF TMR0,W
MOVF TMR0,W MOVF TMR0,W
MOVF TMR0,W
Write TMR0
executed
Read TMR0
reads NT0
Read TMR0
reads NT0
Read TMR0
reads NT0
Read TMR0
reads NT0 + 1
Read TMR0
reads NT0 + 2
Instruction
Executed
PC-1
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
PC
(Program
Counter)
Instruction
Fetch
Timer0
PC
PC+1
PC+2
PC+3
PC+4
PC+5
PC+6
T0
NT0+1
MOVWF TMR0
MOVF TMR0,W
Write TMR0
executed
Read TMR0
reads NT0
Read TMR0
reads NT0
Read TMR0
reads NT0
Read TMR0
reads NT0
Read TMR0
reads NT0 + 1
T0+1
NT0
Instruction
Execute
T0