Cart New Account Login

HomeAbout usProductsSupportForumsBlogCustomer Service

Please accept the use of cookies on our site

At PEmicro we use web browser cookies in order to provide you with an enhanced experience and in order to be able to do things like shopping cart processing and identify you when you login to our website.

Click here to accept

search inside this forum
search inside all forums
USB Multilink Cause Illegal Instruction
Robert R. Sep 29, 2016 at 04:36 PM (16:36 hours)
Staff: Gerardo R.

  • Hi, I have a system with a Coldfire MCF51JM32 in it.  I am using a USB Multilink to debug.  I came across a very strange issue in the last couple days.  I was trying to debug an interface to an SPI Flash chip.  I had had this working before but had changed the way the SPI channel was passed to the routines that handled the commands.  I got it all work, erase sector, read page, write page but when I went to do a combination of these commands all at once I started getting illegal instruction breakpoints.  This happened after I issued the erase sector command so I thought maybe I had some bad decoupling which really would surprise me as this was all working in the past.  So, I have spend the last two days checking the power, decoupling, adding some larger caps near the Flash, etc.  No luck.  I have looked at the power on the scope and seen no drops or spikes.  I went back to a previous revision we did a lot of work on that utilized the Flash and it too failed.  Finally today I tried to let the unit boot up without the Multilink attached and it booted just fine.  I could tell because the Windows computer recognized the USB which is initialized after I run the Flash test code that was failing.  So, I am at a loss to explain why the Multilink causes the code to generate an illegal instruction when connected while I am trying erase the Flash. This makes trying to debug some of the other code really difficult.  Thanks,


  • Sorry, can you provide the following so I can better understand the situation.

    -What software are you using and seeing an issue with? Also provide the version number if applicable.
    -Are you getting an error message? If so, provide the exact text of the error message and where it came from. A screenshot would be ideal.

    • Hi, I am not sure what you mean by "software version", what software?  Also, no, I do not get any error message.  The software stops running, the command window shows ILLEGAL_BP.  I can send the schematics if you like but I have the board very well bypassed.  For IDE I am running Codewarrior 6.3 on XP. I have a screen shot but how do I upload it to this discussion?  Here is the info from the about box: 

      Web: <>;
      License File: D:\Freescale\CW6.3\license.dat
      Application FLEXlm License Version: 2.000, 8.4a
      Vendor daemon: metrowks
      HI409284 (metrowks, 6.000): ColdFire ANSI-C Debug (M68k, limited by feature: 65536 bytes of code, Single User License, ANY, UNREGISTERED)
      HI409285 (metrowks, 6.000): ColdFire C++ Debug (M68k, checkout failed, demo mode: 1024 bytes of code, running in demo mode(-5), UNREGISTERED)
      No such feature exists
      Feature: HI409285
      License path: D:\Freescale\CW6.3\license.dat
      FLEXlm error: -5,357
      For further information, refer to the FLEXlm End User Manual,
      available at "";.

      • One more thing, I do not get an illegal instruction break if I do not have a break point set.  I tried running my code this morning but downloading with the debugger and then just telling it to run.  I downloaded data over the USB to the SPI Flash chip with no illegal instruction interrupt or break.  Is this issue being looked at or should I just move on?  Thanks,

  • Thanks for that information. I'd like to reproduce the issue here to see what might be going wrong, but it's difficult without having the exact Coldfire + SPI flash configuration available to test. Is it at all possible to send us a board for debugging?

    • Where do you want me to keep communicating with you?  I thought you said in the Support Request but you have not answered me in 2 days after my posts and request for more help.  I really could use some help figuring this issue out as it does not seem to be my hardware.  I will keep trying things but I am flying blind somewhat.  I wish you would respond to one of my posts.  Thanks,

  • Yes, I can but let me try one other thing first.  I am running XP on a virtual machine under VMWare Workstation.  Its been working fine up to now but I want to try my one laptop that will still run XP natively to see if that fixes the issue. I am trying to get all the software loaded to try that as fast as I can. Thanks.

Add comment

   Want to comment? Please login or create a new PEMicro account.

© 2018 P&E Microcomputer Systems Inc.
Website Terms of Use and Sales Agreement