USBDM  V4.12
Programming devices while preserving data

Example issues with FXTH87xx11/FXCTH87xx02

Some devices require programming ranges of the Flash memory while preserving other areas. A good example of this is the FXTH87xx11.
The FXTH87xx11 comes pre-programmed with utility code that user programs are meant to access so it is necessary to program only part of the Flash.

Creating a reference image

Before playing around with this chip I created an image of the chip contents.
This allows the chip to be returned to a "factory fresh" state if the firmware is accidentally erased.

  • Use UsbdmMemoryDump to obtain a reference copy of the flash from 0xC000 to 0xFFFF

Using the stand-alone programmer

The USBDM HCS08 Programmmer provides two entries for use with this device:

  • FXTH87xx11-Full-Erase
    This is a device entry that allows completely unprotected programming of the device. This can be used to re-program the device with the above image using mass-erase.
  • FXTH87xx11
    This is an entry that only allows programming the intended user area of the Flash.
    Due to limitations in the USBDM programmer it is not possible to prevent you from mass-erasing the device - You have to manually select selective erase.

To restore an accidentally erased device

  • Load the above image FXTH870511_Image.sx
    • Select FXTH87xx11-Full-Erase as the device
  • Select Image for security
  • Select EraseMass
  • Program and verify to check it's OK

To program a user program (restricted to user flash area)

  • Load the user image file.
    This image should only correspond to the user programmable area of the device.
  • Select FXTH87xx11 as the device
  • Select Image for security
  • Select EraseSelective
  • Program and verify to check it's OK

To use with Codewarrior 10.x

  • Create a project in usual way with a USBDM target interface.
  • Modify the USBDM options as shown below
    • Security field from flash image (there won't be one)
    • Selective erase (by sector)
  • You should be able to debug in the usual fashion

Reference images

I have attached the images from the two chips I used for testing in case you accidentally erase yours before you have made an image.
This should be considered a last resort as the images contains calibration data that will not be correct for another chip: