Figure 37. Int0 Mode 1 Interrupt Sequence - ZiLOG Z8018 Series User Manual

disabling all maskable interrupts. The interrupt service routine normally
terminates with the EI (Enable Interrupts) instruction followed by the
RETI (Return from Interrupt) instruction, to reenable the interrupts.
Figure 37 depicts the use of INT0 (Mode 1) and RETI for the Mode 1
interrupt sequence.
Figure 37. INT0 Mode 1 Interrupt Sequence
Main
Program
INT0
(Mode 1)
Figure 38 illustrates INT0 Mode 1 Timing.
Family MPU User Manual
→
0 EF1, EF2
→
PCH (SP-1)
→
PCL (SP-2)
← (SP)
PCL
← (SP+1)
PCH
Z8018x
0038H
INT0 (Mode 1)
Interrupt Service
Program
→
E1 (1 1EF1, 1EF2)
RETI
UM005004-0918
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