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USB CDC bf703 nonrtos driver problem

Question asked by sgeorge on Nov 3, 2016
Latest reply on Nov 24, 2016 by Jithul_Janardhanan



We are developing our own USB CDC driver for bf703.

This is working fine but there is the glitch.


When our device (bf703) is connected to host (Windows 7) BUT terminal program is not running - bt503 stops send messages via BULK IN data endpoint (after 1-2 min and about 20-30 msgs). It's mean that TXPKTRDY (and NEFIFO set as well) has never became "0" till we run terminal program on host. Also we cant flush tx fifo (by setting FLUSHFIFO bit).


I hope description below could help understand what I mean:


(A terminal program (like hyperterminal) is not running and USB CDC device successfully installed and configured).


1) fill tx buffer (user heap);

2) prepare USB DMA 0 transfer size = size of TXMAXP;

3) run DMA;

4) on DMA callback we set TXPKTRDY = 1 for data loaded in FIFO;

5) wait until TXPKTRDY = 0;

6) repeat from 2 till end of data.


The problem is 2) - TXPKTRDY has never became 0.


Could someone help me?