z80189 ZiLOG Semiconductor, z80189 Datasheet - Page 92

• Manufacturer Part Number: z80189
• Description: Z80180, Z8s180, Z8l180 Mpu Operation
• Manufacturer: ZiLOG Semiconductor

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.
Figure 38 illustrates INT0 Mode 1 Timing.
(Mode 1)
INT0
INT0 Mode 1 Interrupt Sequence
Program
Main
PCL
PCH
PCH
0
PCL
¬ (SP)
¬ (SP+1)
®
®
®
(SP-2)
(SP-1)
EF1, EF2
Family MPU User Manual
0038H
RETI
E1 (1
INT0 (Mode 1)
Interrupt Service
Program
UM005003-0703
®
1EF1, 1EF2)
Z8018x
77