227
Chapter 7
Interrupt/Exception Processing Function
User’s Manual U16580EE3V1UD00
7.2.2 Restore
Execution is restored from the non-maskable interrupt (NMI) processing by the RETI instruction.
When the RETI instruction is executed, the CPU performs the following processing, and transfers
control to the address of the restored PC.
<1> Restores the values of the PC and the PSW from FEPC and FEPSW, respectively, because the
EP bit of the PSW is 0 and the NP bit of the PSW is 1.
<2> Transfers control back to the address of the restored PC and PSW.
Figure 7-3 illustrates how the RETI instruction is processed.
Figure 7-3:
RETI Instruction Processing
Caution:
When the PSW.EP bit and PSW.NP bit are changed by the LDSR instruction during
non-maskable interrupt processing, in order to restore the PC and PSW correctly
during recovery by the RETI instruction, it is necessary to set PSW.EP back to 0 and
PSW.NP back to 1 using the LDSR instruction immediately before the RETI
instruction.
Remark:
The solid line indicates the CPU processing flow.
PSW.EP
RETI instruction
PSW.NP
Original processing restored
1
1
0
0
PC
PSW
EIPC
EIPSW
PC
PSW
FEPC
FEPSW
Summary of Contents for MuPD70F3187
Page 6: ...6 Preface User s Manual U16580EE3V1UD00 ...
Page 16: ...16 User s Manual U16580EE3V1UD00 ...
Page 28: ...28 User s Manual U16580EE3V1UD00 ...
Page 32: ...32 User s Manual U16580EE3V1UD00 ...
Page 84: ...84 Chapter 2 Pin Functions User s Manual U16580EE3V1UD00 MEMO ...
Page 144: ...144 Chapter 3 CPU Functions User s Manual U16580EE3V1UD00 MEMO ...
Page 312: ...312 Chapter 9 16 Bit Timer Event Counter P User s Manual U16580EE3V1UD00 MEMO ...
Page 534: ...534 Chapter 11 16 bit Timer Event Counter T User s Manual U16580EE3V1UD00 ...
Page 969: ...969 Chapter 20 Port Functions User s Manual U16580EE3V1UD00 MEMO ...
Page 970: ...970 Chapter 20 Port Functions User s Manual U16580EE3V1UD00 ...
Page 976: ...976 Chapter 22 Internal RAM Parity Check Function User s Manual U16580EE3V1UD00 MEMO ...
Page 984: ...984 Chapter 23 On Chip Debug Function OCD User s Manual U16580EE3V1UD00 MEMO ...
Page 1006: ...1006 Chapter 24 Flash Memory User s Manual U16580EE3V1UD00 MEMO ...
Page 1036: ...1036 Chapter 27 Recommended Soldering Conditions User s Manual U16580EE3V1UD00 MEMO ...
Page 1046: ...1046 Appendix A Index User s Manual U16580EE3V1UD00 MEMO ...
Page 1052: ...1052 User s Manual U16580EE3V1UD00 ...
Page 1053: ......