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Can same program be used if replaced between Spec. H & L products?

Latest Updated:04/11/2008


(MCU Comparison, Migration)  Can the same program be used unchanged when replacing between the standard, Spec. H, and Spec. L products of the 3804 Group? [2008/04/11]


Basic program contents are described below.
Please note that memory capacity differs by product. For detailed product specifications, refer to datasheets and 3804 Group technical updates. In addition, test the operation of replaced products.

Product Numbers

  Standards Spec. H Spec. L
- -
Flash memory M38049FFSP/FP/HP M38049FFHSP/FP/HP/KP M38049FFLSP/HP/KP/WG

Note: Program checksum

When calculating the checksum of ROM area using a program, make sure to check for differences in target calculation areas.
When the unused area and reserved ROM area are included in target areas of replaced products, the read values are undefined and calculated values of the checksum are also undefined.

(1) Standard Flash Memory version → Spec.L Flash Memory version

  1. When using addresses FFD4h to FFDAh, check the following:
          The code written in these addresses is the ID code of the Spec.L Flash Memory version
          when using a serial programmer. This code must be input as the ID code when reprogramming
          flash memory using a serial programmer. Since the code in these addresses can be executed
          as instructions, they only need to be checked when using a serial programmer.
  2. Bits 7 to 2 of address FFDBh are the protect set bits of the Spec.L Flash Memory version when using a parallel programmer. If you do not want these bits to be set, you must change the program. However, since the protect set bits do not have any effect when a serial programmer is in use, changing them is not essential. As with addresses FFD4h to FFDAh, this address can be used to execute instructions.
  3. If a program accesses addresses 0FE0h to 0FEFh, it must be changed to not access these addresses.
  4. In the Spec.L Flash Memory version, nothing is assigned to addresses 0FFEh and 0FFFh, so program changes are unnecessary even if programming had been performed in the Standard Flash Memory version.
  5. Program changes are necessary when the oscillation stabilization time after the STP instruction is released is less than 100μsec in stop mode. Set the oscillation stabilization time setting for after the release of the STP instruction which uses timer 1 to 100μsec or more.
  6. When using CPU rewrite mode, overall changes to the related processes are necessary.

(2) Spec.H Flash Memory version → Spec.L Flash Memory version

Program changes are unnecessary.

Suitable Products