Datasheet

Table Of Contents
PIC16F631/677/685/687/689/690
DS41262E-page 210 © 2008 Microchip Technology Inc.
FIGURE 14-8: INT PIN INTERRUPT TIMING
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 GIE PEIE T0IE INTE RABIE T0IF INTF RABIF 0000 000x 0000 000x
PIE1
ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE -000 0000 -000 0000
PIE2 OSFIE C2IE C1IE EEIE
0000 ---- 0000 ----
PIR1
ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF -000 0000 -000 0000
PIR2
OSFIF C2IF C1IF EEIF 0000 ---- 0000 ----
Legend: x = unknown, u = unchanged, = unimplemented read as ‘0’, q = value depends upon condition.
Shaded cells are not used by the Interrupt module.
Q2Q1 Q3 Q4 Q2Q1 Q3 Q4 Q2Q1 Q3 Q4 Q2Q1 Q3 Q4 Q2Q1 Q3 Q4
OSC1
CLKOUT
INT pin
INTF flag
(INTCON<1>)
GIE bit
(INTCON<7>)
INSTRUCTION FLOW
PC
Instruction
Fetched
Instruction
Executed
Interrupt Latency
PC PC + 1
PC + 1
0004h
0005h
Inst (0004h)
Inst (0005h)
Dummy Cycle
Inst (PC)
Inst (PC + 1)
Inst (PC – 1)
Inst (0004h)
Dummy Cycle
Inst (PC)
Note 1: INTF flag is sampled here (every Q1).
2: Asynchronous interrupt latency = 3-4 T
CY. 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.
(1)
(2)
(3)
(4)
(5)
(1)