PIC16C8X Datasheet, PDF (48/117 Pages) Microchip Technology – 8 BIT CMOS EEPROM MICROCONTROLLERS

PIC16C8X
FIGURE 8-16: INTERRUPT LOGIC
T0IF
T0IE
INTF
INTE
RBIF
RBIE
EEIF
EEIE
GIE
Wake-up
(If in SLEEP mode)
Interrupt to CPU
FIGURE 8-17: INT PIN INTERRUPT TIMING
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
OSC1
CLKOUT 3
4
INT pin
1
INTF flag
5
(INTCON<1>)
GIE bit
(INTCON<7>)
INSTRUCTION FLOW
PC
PC
Instruction
fetched
Inst (PC)
Instruction
executed
Inst (PC-1)
1
Interrupt Latency ₂
PC+1
Inst (PC+1)
Inst (PC)
PC+1
—
Dummy Cycle
0004h
Inst (0004h)
Dummy Cycle
0005h
Inst (0005h)
Inst (0004h)
Note 1: INTF flag is sampled here (every Q1).
2: Interrupt latency = 3-4Tcy where Tcy = instruction cycle time.
Latency is the same whether Inst (PC) is a single cycle or a 2-cycle instruction.
3: CLKOUT is available only in RC oscillator mode.
4: For minimum width of INT pulse, refer to AC specs.
5: INTF is enabled to be set anytime during the Q4-Q1 cycles.
DS30081F-page 48
© 1995 Microchip Technology Inc.