lpcware

USB ROM  Comprehensive Bug List ???

Discussion created by lpcware Employee on Jun 15, 2016
Content originally posted in LPCWare by geoffreymbrown on Mon Mar 30 11:49:41 MST 2015
I've been working on CDC and HID applications using the LPC USB ROM on the 11u24 parts.  As noted widely in these forums there are significant bugs in this ROM; however, it is never clear which parts the bugs apply to.  Furthermore, the published example code contains both clearly marked workarounds as well as code suggestive of a work around.  But again no documentation.   Bugs I believe exist include

1)  Memory allocation -- the hw api memory allocation routine seems to parse descriptor files to allocate memory and doesn't handle the case with multiple configurations correctly.

2) Bugs listed in this errata http://www.nxp.com/documents/errata_sheet/ES_LPC11U2X.pdf

3) It seems the CDC init routine has bugs related to user defined endpoint handler -- at least most examples configure these separately even though the cdc init structure provides for them

Then there are things that matter, but aren't documented

it's never made clear what the behavioral model is for the ROM stack.  For example if I execute

ReadReqEp and don't read all the available data, is the underlying buffer freed ?

Is there any comprehensive documentation about what bugs exist, for what parts, and recommended workarounds ?

Outcomes