Qing Gu

USB CDC failed when MCF51JM128 enters wait mode without BDM

Discussion created by Qing Gu on Mar 18, 2011
Latest reply on Apr 6, 2011 by Gustavo Denardin

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.

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