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STM32F USB Firmware (cdc class driver) bug (64 byte transfers from device to host)

Question asked by andersson.mikael.003 on Mar 21, 2013
Latest reply on Mar 22, 2013 by xu.jie.001
Hi,
64 byte transfers from my STM32F4 cdc driver to the host side fails. 63 bytes work, as well as 65 bytes.

A quick forum search indicates that this is a bug in the cdc class driver firmware. A 64 byte transfer should be followed by a 0-byte transfer so that the host side (windows) can detect end of transfer. So, this bug is known but I have so far failed to find a fix for it. Does anyone know how to fix it - or is there a firmware library out there somewhere where this is fixed already?

Currently I'm using
"STM32_USB-Host-Device_Lib_V2.1.0", V1.1.0 / 19-March-2012

Best regards,
Mikael

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