GMS82524 Datasheet, PDF (53/93 Pages) Hynix Semiconductor – 8-BIT SINGLE-CHIP MICROCONTROLLERS

GMS82512/16/24
HYUNDAI MicroElectronics
area for saving registers.
The following method is used to save/restore the general-
purpose registers.
Example: Register save using push and pop instructions
INTxx: PUSH A
PUSH X
PUSH Y
interrupt processing
POP
Y
POP
X
POP
A
RETI
;SAVE ACC.
;SAVE X REG.
;SAVE Y REG.
;RESTORE Y REG.
;RESTORE X REG.
;RESTORE ACC.
;RETURN
General-purpose register save/restore using push and pop
instructions;
main task
acceptance of
interrupt
interrupt
service task
saving
registers
interrupt return
restoring
registers
14.2 BRK Interrupt
Software interrupt can be invoked by BRK instruction,
which has the lowest priority order.
Interrupt vector address of BRK is shared with the vector
of TCALL 0 (Refer to Program Memory Section). When
BRK interrupt is generated, B-flag of PSW is set to distin-
guish BRK from TCALL 0.
Each processing step is determined by B-flag as shown in
Figure 14-5.
BRK or
TCALL0
B-FLAG
=1
BRK
INTERRUPT
ROUTINE
=0
TCALL0
ROUTINE
RETI
RET
Figure 14-5 Execution of BRK/TCALL0
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