231
Chapter 7
Interrupt/Exception Processing Function
User’s Manual U16580EE3V1UD00
7.3.2 Restore
Recovery from maskable interrupt processing is carried out by the RETI instruction.
When the RETI instruction is executed, the CPU performs the following steps, and transfers control to
the address of the restored PC.
(1) Restores the values of the PC and the PSW from EIPC and EIPSW because the EP bit of the
PSW is 0 and the NP bit of the PSW is 0.
(2) Transfers control to the address of the restored PC and PSW.
Figure 7-7 illustrates the processing of the RETI instruction.
Figure 7-7:
RETI Instruction Processing
Note:
For the ISPR register, see
7.3.6 ”In-service priority register (ISPR)” on page 242
Caution:
When the PSW.EP bit and the PSW.NP bit are changed by the LDSR instruction
during 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 0 using the LDSR instruction immediately before the RETI
instruction.
Remark:
The solid lines show the CPU processing flow.
PSW.EP
RETI instruction
PSW.NP
Restores original processing
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 ...
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