# CW support for MC9S12DG256C

Question asked by Gerrit Barrere on Oct 25, 2016
Latest reply on Oct 30, 2016 by ZhangJennie

Hello all,

I'm supporting a legacy processor with an older version of CodeWarrior (CW12 v3.1) on an XP laptop.  I'm trying to get debugging going using a USB Multilink from P&E Micro, but I can't connect with the processor.  CW connects to the Multilink but I get 'FP: MpuDesc invalidated' errors and it disconnects.

I think this is because new production is using the 'DG256C version of this processor, but my CW only shows the 'DG256B version under ICD-12 / Set Derivative.  It tells me the MCUID of this derivative is 0x3D9, and I suspect the C is something different.

I see a number of derivative files in C:\Program Files\Metrowerks\CodeWarrior CW12_V3.1\prog\REG, including one named mcu03D9.reg  for the MC9S12DG256B.  It looks like all I need is the .reg file for the C version.  Can anyone help?

Many thanks,

Gerrit