Program Example For The External Interrupt Circuit - Fujitsu Semiconductor Controller MB89950/950A Hardware Manual

CHAPTER 11 EXTERNAL INTERRUPT CIRCUIT (EDGE)
11.6

Program Example for the External Interrupt Circuit

This section gives a program example for the external interrupt circuit.
I Program example for the external interrupt circuit
G
Processing description
• Generates interrupts on detecting a rising edge on pulses input to the INT1 pin.
G
Coding example
EIC1
EIR1
SL10
EIE1
ILR1
INT_V
IRQ1
INT_V
;-----Main program----------------------------------------------------------------
;-----Interrupt processing routine------------------------------------------------
WARI
;---------------------------------------------------------------------------------
232
EQU 0030H
EQU EIC1:7
EQU EIC1:5
EQU EIC1:4
EQU 007CH
DSEG ABS
ORG 0FFF8H
DW WARI
ENDS
CSEG
:
CLRI
CLRB EIR1
MOV ILR1,#11110111B ; Set interrupt level (level 1).
SETB SL10
SETB EIE1
SETI
:
CLRB EIE1
PUSHW A
XCHW A,T
PUSHW A
:
User processing
:
POPW A
XCHW A,T
POPW A
RETI
ENDS
END
; External interrupt control register 1
; Defines the external interrupt request flag bit.
; Defines the edge polarity selection bit.
; Defines the interrupt request enable bit.
; Set interrupt level setting register 1.
; [DATA SEGMENT]
; Set INT1 interrupt vector.
; [CODE SEGMENT]
; Stack pointer (SP) etc. are already initialized.
; Disable interrupts.
; Clear interrupt request flag.
; Select rising edge.
; Enable output of interrupt requests.
; Enable interrupts.
; Clear INT1 interrupt request flag.