Datasheet

PIC16C71X
DS30272A-page 32  1997 Microchip Technology Inc.
FIGURE 6-3: TIMER0 TIMING: INTERNAL CLOCK/PRESCALE 1:2
FIGURE 6-4: TIMER0 INTERRUPT TIMING
PC+
6
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
TMR0
PC PC+1 PC+2 PC+3 PC+4 PC+5 PC+6
T0 NT0+1
MOVWF TMR0
MOVF TMR0,W 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
Read TMR0
reads NT0 + 1
T0+1
NT0
Instruction
Execute
Q2Q1 Q3 Q4Q2Q1 Q3 Q4 Q2Q1 Q3 Q4 Q2Q1 Q3 Q4 Q2Q1 Q3 Q4
1
1
OSC1
CLKOUT(3)
Timer0
T0IF bit
(INTCON<2>)
FEh
GIE bit
(INTCON<7>)
INSTR
UCTION
PC
Instruction
fetched
PC
PC +1 PC +1 0004h 0005h
Instruction
executed
Inst (PC)
Inst (PC-1)
Inst (PC+1)
Inst (PC)
Inst (0004h) Inst (0005h)
Inst (0004h)Dummy cycle Dummy cycle
FFh 00h 01h 02h
Note 1: Interrupt flag bit T0IF is sampled here (every Q1).
2: Interrupt latency = 4Tcy where Tcy = instruction cycle time.
3: CLKOUT is available only in RC oscillator mode.
FLO
W