PIC16C432
FIGURE 6-3:
TIMER0 TIMING: INTERNAL CLOCK/PRESCALE 1:2
PC
(Program
Counter)
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-1
PC
PC+1
PC+2
PC+3
PC+4
PC+5
PC+6
Instruction
Fetch
MOVWF TMR0 MOVF TMR0,W MOVF TMR0,W MOVF TMR0,W MOVF TMR0,W MOVF TMR0,W
TMR0
T0
T0+1
NT0
NT0+1
Instruction
Execute
Write TMR0 Read TMR0 Read TMR0 Read TMR0 Read TMR0 Read TMR0
executed reads NT0 reads NT0 reads NT0 reads NT0 reads NT0 + 1
FIGURE 6-4:
TIMER0 INTERRUPT TIMING
OSC1
CLKOUT(3)
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
TMR0 Timer
FEh
FFh
00h
01h
02h
T0IF bit
1
1
(INTCON<2>)
GIE bit
(INTCON<7>)
INSTRUCTION FLOW
PC
PC
Instruction
Fetched
Inst (PC)
Instruction
Executed
Inst (PC-1)
PC +1
Inst (PC+1)
Inst (PC)
Interrupt Latency Time
PC +1
Dummy cycle
0004h
Inst (0004h)
Dummy cycle
0005h
Inst (0005h)
Inst (0004h)
Note 1: T0IF interrupt flag is sampled here (every Q1).
2: Interrupt latency = 3Tcy, where Tcy = instruction cycle time.
3: CLKOUT is available only in RC Oscillator mode.
DS41140C-page 28
Preliminary
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