The part number of your FLASH indicates that it has a Top (T) boot block. For this to be useful in your application you need to be using an MCU that has its power on reset vector in the top of its address space.

This flash is not one of the types that support simultaneous code fetching and programming/erase cycles. To use this your boot loader will have to move a short code sequence that accesses the FLASH into another memory space for execution. A quick look at the M16C/62P data sheet would seem to suggest that the internal RAM of the part can be used for executing code in addition to being used for stack and data storage. (Do not base your design on my comment however and verify for your self that code can execute from the RAM).

Do note that Renesas at their web site do not recommend the M16C/62P series for use in new designs.

Using these parts in a design where you make a small volume and hope to be able to purchase the parts over an extended period of time is not something I would recommend with these parts. There are so many variants of parts made that any one given type can disappear at the drop of a hat.

Michael Karas