Zilog Z80180 - Manual (Page 89)

Z8018x
Family MPU User Manual
74
UM005003-0703
Figure 34. NMI Use
Main
Program
NMI
EF1
0
PCH
EF1
PCL
PCL
PCH
NMI
Interrupt Service
Program
0066H
RETN
® (SP-2)
® (SP-1)
® EF1
® EF2
¬ EF2
¬ (SP)
¬ (SP+1)
Phi
A0 – A19
WR
RD
MREQ
D0 – D7
MI
PCH PCL
Instruction
Last MC NMI acknowledge cycle
PC is pushed onto stack Restart from 0066H
Op Code fetch
PC SP-1 SP-2 0066H
NMI
T1 T3 Ti T1 T1 T2 T3 T1 T2 T3 T1 T1 T2 T3