topic Re: USB CDC failed when MCF51JM128 enters wait mode without BDM in ColdFire/68K Microcontrollers and Processors

USB CDC failed when MCF51JM128 enters wait mode without BDM

z3 — Fri, 18 Mar 2011 21:38:06 GMT

We are using CMX USB-lite CDC driver on the ColdFire chip. With the BDM and Hiwave debugger running, the USB code works in wait mode. But without the BDM, the Host PC still enumerates our device but the COM port cannot be used. With BDM, our device draws 10mA more current which leads me to believe the MCU is still clocked. In fact, Ref. Manual says the MCU is clocked in stop modes if XCSR[BDMEN] bit is set.

We could not find anything that says definitely USB does or does not work in wait mode.

Re: USB CDC failed when MCF51JM128 enters wait mode without BDM

gustavod — Wed, 06 Apr 2011 00:29:31 GMT

Hi z3,

We are facing very same problem. The reference manual said that USB is clocked in wait mode.

Anyone faced the same problem?

We are testing the code in the Freescale TWR-LCD kit. The source code is available in:

http://brtos.googlecode.com/files/TWR-LCD-FatFS.rar

This is a demo of BRTOS (real-time operating system) with eGUI, FAT32, SD card and CMX USB stack with CDC class (serial terminal).

Re: USB CDC failed when MCF51JM128 enters wait mode without BDM

gustavod — Wed, 06 Apr 2011 18:56:09 GMT

I forgot to say that to activate the "wait mode " is necessary to change the define DEBUG from 0 to 1 in the BRTOSConfig.h file.