PIC14000-04 Microchip Technology, PIC14000-04 Datasheet - Page 84

• Manufacturer Part Number: PIC14000-04
• Description: 28-Pin Programmable Mixed Signal Controller
• Manufacturer: Microchip Technology

PIC14000
10.6.2
An overflow (FFh
(INTCON<2>)
enables the interrupt.
10.6.3
An input change on PORTC<7:4> sets RCIF
(PIR1<2>). Setting RCIE (PIE1<2>) enables the inter-
rupt. For operation of PORTC, refer to Section 5.2.
EXAMPLE 10-1: SAVING STATUS AND W REGISTERS IN RAM
DS40122B-page 84
Note:
MOVWF
SWAPF
BCF
BCF
MOVWF
:
:(ISR)
:
SWAPF
MOVWF
SWAPF
SWAPF
TIMER0 INTERRUPT
PORTC INTERRUPT ON CHANGE
If a change on the I/O pin should occur
when the read operation is being executed
(start of the Q2 cycle), then the RCIF
interrupt flag may not be set.
flag.
W_TEMP
STATUS,W
STATUS,RP1
STATUS,RP0
STATUS_TEMP
STATUS_TEMP,W
STATUS
W_TEMP,F
W_TEMP,W
00h) in Timer0 will set the T0IF
Setting
T0IE
;Copy W to TEMP register, could be any bank
;Swap status to be saved into W
;Change to bank zero, regardless of current bank
;
;Save status to bank zero STATUS_TEMP register
;Swap STATUS_TEMP register into W
;(sets bank to original state)
;Move W into STATUS register
;Swap W_TEMP
;Swap W_TEMP into W
(INTCON<5>)
Preliminary
10.6.4
During an interrupt, only the return PC value is saved
on the stack. Typically, users may wish to save key
registers during an interrupt, for example, W register
and Status register. Example 10-1 is an example that
shows saving registers in RAM.
CONTEXT SWITCHING DURING
INTERRUPTS
1996 Microchip Technology Inc.