z80189 ZiLOG Semiconductor, z80189 Datasheet - Page 89

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

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UM005003-0703
Z8018x
Family MPU User Manual
A0
D0
MREQ
–
–
NMI
A19
WR
Phi
RD
D7
MI
Last MC
Figure 34.
T1
NMI
NMI Use
T1
Program
NMI acknowledge cycle
Main
T3
PC
Ti
EF1
PCL
PCH
T1
EF1
0
PCH
PCL
T1
PC is pushed onto stack
¬
¬
¬
®
®
®
®
(SP)
(SP+1)
EF2
EF2
(SP-1)
EF1
T2
(SP-2)
SP-1
PCH
T3
T1
T2
SP-2
PCL
T3
0066H
T1 T2
RETN
Restart from 0066H
Instruction
Op Code fetch
0066H
NMI
Interrupt Service
Program
T3