EIT
4
4.6 Saving and Restoring the PC and PSW
[1] Saving the SM, IE and C bits
[3] Saving the PC
BSM
BIE
BC
←
←
←
SM
IE
BPC
←
PC
[4] Setting the vector address in the PC
PC
C
←
Vector address
[2] Updating the SM, IE and C bits
SM
IE
←
←
←
Unchanged or 0
0
0
C
[A] Restoring the SM, IE and C bits from the
backup field
[B] Restoring the PC from the BPC register
SM
IE
←
←
←
BSM
BIE
BC
The value stored in the BPC register
after executing the RTE instruction is
undefined.
C
The values stored in the BSM, BIE
and BC bits after executing the RTE
instruction are undefined.
PSW
BPC
PC
[4]
[1]
[3]
When EIT is accepted
[2]
When RTE instruction
[A]
[B]
is executed
BPSW field
PSW field
0(MSB)
7
8
15 16 17
23 24 25
31(LSB)
PSW 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
BSM
BIE
BC
SM
IE
C
Figure 4.6.1 Saving and Restoring the PC and PSW
32180 Group User’s Manual (Rev.1.0)
4-9
RENESAS [ RENESAS TECHNOLOGY CORP ]
