Figure 34. Nmi Use - ZiLOG Z8018 Series User Manual

Z8018x
Family MPU User Manual
74
Phi
NMI
–
A0 A19
–
D0 D7
MI
MREQ
RD
WR
UM005004-0918
Main
Program
NMI
Figure 34. NMI Use
Last MC
NMI acknowledge cycle
T1 T1 T3
PC
→
EF1 EF2
→
0 EF1
→
PCH (SP-1)
→
PCL (SP-2)
←
EF1 EF2
←
PCL (SP)
←
PCH (SP+1)
PC is pushed onto stack
Ti T1 T1 T2 T3 T1
SP-1
PCH
0066H
NMI
Interrupt Service
Program
RETN
Restart from 0066H
Op Code fetch
T2 T3 T1 T2 T3
SP-2
0066H
Instruction
PCL