SN8P1600
8-bit micro-controller
INT0 (P0.0) INTERRUPT OPERATION
The INT0 has falling edge interrupt trigger. For SN8P1600, the INT0 just uses the falling edge to trigger the external
interrupt 0. When the INT0 trigger occurs, the P00IRQ will be set to “1” however the P00IEN is enable or disable. If the
P00IEN = 1, the trigger event sets the P00IRQ to be “1” and the system into interrupt vector (ORG 8). If the P00IEN =
0, the trigger event just only sets the P00IRQ to be “1” but the system doesn’t get into interrupt vector. Users need to
care the operation under multi-interrupt situation.
ꢃ
Example: INT0 interrupt request setup.
B0BSET
B0BCLR
B0BSET
FP00IEN
FP00IRQ
FGIE
; Enable INT0 interrupt service
; Clear INT0 interrupt request flag
; Enable GIE
ꢃ
Example: INT0 interrupt service routine.
ORG
JMP
8
; Interrupt vector
INT_SERVICE
INT_SERVICE:
B0XCH
B0MOV
B0MOV
A, ACCBUF
A, PFLAG
PFLAGBUF, A
; Store ACC value.
B0BTS1
JMP
FP00IRQ
EXIT_INT
; Check P00IRQ
; P00IRQ = 0, exit interrupt vector
B0BCLR
FP00IRQ
; Reset P00IRQ
.
.
.
.
; INT0 interrupt service routine
EXIT_INT:
B0MOV
B0MOV
B0XCH
A, PFLAGBUF
PFLAG, A
A, ACCBUF
; Restore ACC value.
; Exit interrupt vector
RETI
SONiX TECHNOLOGY CO., LTD
Page 68
Revision 1.94
SONIX [ SONIX TECHNOLOGY COMPANY ]
