Z80180 Datasheet, PDF (89/326 Pages) Zilog, Inc. – Z8018x Family MPU

Z 8018x Fam ily
M PU Us e r M anual
74
Main
Program
EF1 → EF2
0 → EF1
PCH → (SP-1)
PCL → (SP-2)
NMI
EF1 ← EF2
PCL ← (SP)
PCH← (SP+1)
Figure 34. NMI Use
0066H
NMI
Interrupt Service
Program
RETN
Phi
NMI
A0–A19
D0–D7
MI
MREQ
RD
WR
Last MC
NMI acknowledge cycle
PC is pushed onto stack
Restart from 0066H
Op Code fetch
T1 T1 T3 Ti T1 T1 T2 T3 T1 T2 T3 T1 T2 T3
PC
SP-1
SP-2
0066H
PCH
PCL
Instruction
UM005001-ZMP0400