PIC16F631_08 Datasheet, PDF (212/306 Pages) Microchip Technology – 20-Pin Flash-Based, 8-Bit CMOS Microcontrollers with nanoWatt Technology

PIC16F631/677/685/687/689/690
FIGURE 14-8:
INT PIN INTERRUPT TIMING
OSC1
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
CLKOUT ⁽³⁾
(4)
INT pin
(1)
INTF flag
(INTCON<1>)
(1)
(5)
GIE bit
(INTCON<7>)
Interrupt Latency ⁽²⁾
INSTRUCTION FLOW
PC
PC
Instruction
Fetched
Inst (PC)
PC + 1
Inst (PC + 1)
PC + 1
—
0004h
Inst (0004h)
0005h
Inst (0005h)
Instruction
Executed
Inst (PC – 1)
Inst (PC)
Dummy Cycle
Dummy Cycle
Inst (0004h)
Note 1: INTF flag is sampled here (every Q1).
2: Asynchronous interrupt latency = 3-4 TCY. Synchronous latency = 3 TCY, 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 INTOSC and RC Oscillator modes.
4: For minimum width of INT pulse, refer to AC specifications in Section 17.0 “Electrical Specifications”.
5: INTF is enabled to be set any time during the Q4-Q1 cycles.
TABLE 14-6: SUMMARY OF INTERRUPT REGISTERS
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR, BOR
Value on
all other
Resets
INTCON
PIE1
PIE2
PIR1
PIR2
Legend:
GIE
PEIE T0IE INTE RABIE T0IF
INTF RABIF 0000 000x
—
ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE -000 0000
OSFIE C2IE C1IE EEIE
—
—
—
—
0000 ----
—
ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF -000 0000
OSFIF C2IF
C1IF
EEIF
—
—
—
—
0000 ----
x = unknown, u = unchanged, — = unimplemented read as ‘0’, q = value depends upon condition.
Shaded cells are not used by the Interrupt module.
0000 000x
-000 0000
0000 ----
-000 0000
0000 ----
DS41262E-page 210
© 2008 Microchip Technology Inc.