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Renesas Electronics Europe - Knowledgebase

How to write MCU and FDT with same data and PC?

Latest Updated:05/14/2007


I am using the same type of MCU, same circuit board, same PC environment, and same flash development tool kit (FDT) to write the same data, yet I get an error for when I do a file comparison (read back verify). Why does this happen and how can I resolve it?


This particular problem occasionally occurs when executing a read back verify for the entire flash area on an M16C Family or 740 Family MCU. When data is written in the FDT initialization state, block erasure and block write are performed. However, if there is data already written to a block other than the block you are programming, the original data cannot be erased by the FDT operation. Therefore, the read back verify of the entire area does not match that original data, and an error occurs.
When this happens, we recommend erasing the entire area and then writing the new data you want to verify. The easiest method is to use the [All erase + download] command in the FDT Basic mode.
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