Datasheet

V850ES/JG3 CHAPTER 19 INTERRUPT/EXCEPTION PROCESSING FUNCTION
R01UH0015EJ0300 Rev.3.00 Page 658 of 870
Sep 30, 2010
19.4.2 Restore
Restoration from software exception processing is carried out by the RETI instruction.
By executing the RETI instruction, the CPU carries out the following processing and shifts control to the restored PC’s
address.
<1> Loads the restored PC and PSW from EIPC and EIPSW because the PSW.EP bit is 1.
<2> Transfers control to the address of the restored PC and PSW.
The processing of the RETI instruction is shown below.
Figure 19-10. RETI Instruction Processing
PSW.EP
RETI instruction
PC
PSW
EIPC
EIPSW
PSW.NP
Original processing restored
PC
PSW
FEPC
FEPSW
1
1
0
0
Caution When the EP and NP bits are changed by the LDSR instruction during the software exception
processing, in order to restore the PC and PSW correctly during recovery by the RETI
instruction, it is necessary to set the EP bit back to 1 and the NP bit back to 0 using the LDSR
instruction immediately before the RETI instruction.
Remark The solid line shows the CPU processing flow.