RX610 Group
9. Exceptions
R01UH0032EJ0120 Rev.1.20
Page 209 of 1006
Feb 20, 2013
9.4
Hardware Processing for Accepting and Returning from Exceptions
This section describes the hardware processing for accepting and returning from exceptions other than a reset.
(1)
Hardware pre-processing for accepting an exception
(a)
Saving the values in the PSW
•
For the fast interrupt
PSW
→
BPSW
•
For other exceptions
PSW
→
Stack area
Note: The values in the FPSW are not saved by hardware pre-processing. Therefore, if floating-point instructions are to be
used within an exception handling routine, the user must ensure that these values are saved on the stack.
(b)
Updating of the PM, U, and I bits in the PSW
I: Cleared
I: Cleared
PM: Cleared
(c)
Saving the values in the PC
•
For the fast interrupt
PC
→
BPC
•
For other exceptions
PC
→
Stack area
(d)
Set the branch-destination address of the exception handling routine in the PC
Processing is shifted to the exception handling routine by acquiring the vector corresponding to the exception and
branching accordingly.
(2)
Hardware post-processing for execution of RTE and RTFI instructions
(a)
Restoring the values in the PSW
•
For the fast interrupt
BPSW
→
PSW
•
For other exceptions
Stack area
→
PSW
(b)
Restoring the values in the PC
•
For the fast interrupt
BPC
→
PC
•
For other exceptions
Stack area
→
PC
Summary of Contents for RX600 Series
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