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Renesas Singapore - Knowledgebase

Reading content in internal flash memory with RX MCU on circuit board

Last Updated:01/31/2018


I’m using an RX family MCU. I want to read out the content written into the internal flash memory while the MCU is mounted in place on a circuit board. Is it possible? If possible, how can I do that?


If the circuit board can communicate with your PC via a PG-FP5, an E1 or E20 emulator, RS-232C or USB interface, it is possible to read out the contents of memory, depending on the state of ID code protection of the MCU.

Please check to see that the following conditions are met.

  • Regarding connection with the circuit board
    Furthermore, the necessary software differs depending on the type of connection as follows:
    • PG-FP5:
      Dedicated programming GUI that comes with the PG-FP5

    • Via JTAG or FINE (E1/E20 emulator):
      CS+ (CubeSuite+) or High-performance Embedded Workshop

    • Via FINE or SCI (E1/E20 emulator) or RS-232C or USB interface:
      Renesas Flash Programmer or Flash Development Tool Kit

    For the USB bootable MCUs in RX621, RX62N, RX630, RX631, RX63N or RX63T group, writing to the internal flash memory through the USB interface by using the Renesas Flash Programmer or Flash Development Tool Kit is possible, but reading is not. For details of the specification, see the chapter "USB Boot Mode" in the user's manual: hardware for each group.

  • Regarding ID code protect

    The ID code protect function of the RX family is the function to disable the internal flash memory from being read out, written to and erased.
    As control code and ID code must have been written into the internal flash memory by the user, once you supply ID code that matches this ID code when you use the debugger or flash programmer, it is possible to start the MCU while retaining the content of the internal flash memory intact, so you can read out the internal flash memory.
    Note, however, that if control code and ID code have not been set by the user, control code and ID code normally are all set to FFh. In this case, memory content can only be read out by the debugger. The above can be summarized in the table below.
      Debugger Flash Programmer
    When ID code protect is not set
    (all FFh)
    Readable Unreadable Note
    When ID code protect is set Readable if ID code matches Readable if ID code matches Note
    Note: RX MCUs have an ID code protection function that can trigger erasure of flash memory, and if ID code protection is not set (all bytes FFh) or a code is set but the ID code does not match in an MCU of this type, all blocks of the internal flash memory are erased.
    If the ID code setting is for erasing all blocks, do not connect the flash programmer to the MCU.

    Refer to the FAQ below for information on how to proceed when you do not know the ID code or the specifications of the control code and ID code.
    FAQ 1000214
Suitable Products
RX Family
CS+ (formerly CubeSuite+)
High-performance Embedded Workshop
E1 [R0E000010KCE00]
E20 [R0E000200KCT00]
Renesas Flash Programmer
Flash Development Toolkit