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Renesas Electronics America - Knowledgebase

Can software with R8C/1x & R8C/2x canbe applied to R8C/3x?

Latest Updated:07/10/2008


Can software that was originally developed for use with the R8C/1x and R8C/2x series also be applied to the R8C/3x series?


The area of addresses FFD8h-FFDBh is a newly reserved area in the R8C/3x series and is not available for user programs.

The variable vector table is assigned to addresses FEDCh to FFDBh, just before the fixed vectors in the default settings for start-up and projects in the R8C/1x and R8C/2x series. This area will overlap with the additional reserved area in the R8C/3x series. Therefore, to use such a program with the R8C/3x series, you will need to move the assigned address of the variable vector table (vector section), such as changing FEDCh to FED8h.

The variable vector table in R8C/3x start-up and projects is assigned to area FED8h to FFD7h to avoid the reserved area.

Option Function Select Register 2 (register 0FS2, address FFDBh) is allocated to this reserved area. If this area overlaps with the variable vector table, an incorrect value will be written to register 0FS2.

For more details concerning register 0FS2, refer to the hardware manual for your target MCU.
For instructions on setting register 0FS2, refer to FAQ 107030.
Suitable Products
C/C++ Compiler Package for M16C Series and R8C Family [M3T-NC30WA]