Precautions On Eit - Renesas M32R/ECU Series User Manual

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4.13 Precautions on EIT

The Address Exception (AE) requires caution because if one of the instructions that use "register indirect + register
update" addressing mode (following three) generates an address exception when it is executed, the values of the
registers to be automatically updated (Rsrc and Rsrc2) become undefined.
Except that the values of Rsrc and Rsrc2 become undefined, these instructions behave the same way as when
used in other addressing modes.
• Applicable instructions
LD Rdest, @Rsrc+
ST Rsrc1, @-Rsrc2
ST Rsrc1, @+Rsrc2
If the above case applies, consider the fact that the register values become undefined when you design the processing
to be performed after executing said instructions. (If an address exception occurs, it means that the system has some
fatal fault already existing in it. Therefore, address exceptions must be used on condition that control will not be returned
from the address exception handler to the program that was being executed when the exception occurred.)
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4.13 Precautions on EIT
32180 Group User's Manual (Rev.1.0)
EIT