PIC16C923-04I/CL Microchip Technology, PIC16C923-04I/CL Datasheet - Page 46

• Manufacturer Part Number: PIC16C923-04I/CL
• Description: 8-Bit CMOS Microcontroller with LCD Driver
• Manufacturer: Microchip Technology

PIC16C9XX
FIGURE 7-3: TIMER0 TIMING: INTERNAL CLOCK/PRESCALE 1:2
FIGURE 7-4: TIMER0 INTERRUPT TIMING
DS30444E - page 46
Instruction
PC
(Program
Counter)
Fetch
Instruction
Execute
TMR0
INSTRUCTION
FLOW
GIE bit
(INTCON<7>)
T0IF bit
(INTCON<2>)
Instruction
fetched
Instruction
executed
Timer0
CLKOUT(3)
OSC1
PC
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
Note 1: Interrupt flag bit T0IF is sampled here (every Q1).
T0
PC-1
Q1
2: Interrupt latency = 4T
3: CLKOUT is available only in RC oscillator mode.
FEh
Inst (PC)
Inst (PC-1)
Q2
1
PC
MOVWF TMR0
Q3
PC
T0+1
Q4
CY
Q1
MOVF TMR0,W
FFh
where T
Write TMR0
executed
Inst (PC+1)
Inst (PC)
PC+1
Q2
1
PC +1
CY
Q3
= instruction cycle time.
MOVF TMR0,W MOVF TMR0,W
Q4
Read TMR0
reads NT0
PC+2
Q1
00h
Dummy cycle
Q2
PC +1
Read TMR0
reads NT0
PC+3
Q3
NT0
Q4
MOVF TMR0,W
Read TMR0
reads NT0
Q1
PC+4
01h
Dummy cycle
Inst (0004h)
Q2
0004h
Q3
MOVF TMR0,W
Read TMR0
reads NT0
1997 Microchip Technology Inc.
PC+5
Q4
Q1
02h
Read TMR0
reads NT0 + 1
Inst (0004h)
Inst (0005h)
NT0+1
Q2
0005h
PC+6
Q3
Q4
PC+6