LPC1347 - CDC data overwrite / overrun

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LPC1347 - CDC data overwrite / overrun

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lpcware
NXP Employee
NXP Employee
Content originally posted in LPCWare by BPC on Thu Jul 11 11:04:27 MST 2013
I am running into what I believe is some type of data overwrite when I call 2 consecutive WriteEP commands.  Unless I put a delay between these commands, some data from the second buffer appears in the USB transfer from the first buffer.  It is also completely random.  Sometimes each command goes through as expected.  Sometimes the data is garbled together.  I am guessing these commands are being called too closely together and violating some spec (USB FS frame rate maybe?).  Any help here would be greatly appreciated.

pUsbApi->hw->WriteEP (hUsb, USB_CDC_EP_BULK_IN, (unsigned char *)&buffer_1[0], strlen(buffer_1));
pUsbApi->hw->WriteEP (hUsb, USB_CDC_EP_BULK_IN, (unsigned char *)&buffer_2[0], strlen(buffer_2));
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lpcware
NXP Employee
NXP Employee
Content originally posted in LPCWare by Tsuneo on Thu Jul 11 20:35:29 MST 2013
LPC1347 shares the same USB engine and the same USB on-chip drivers as LPC11U2x/3x.
And then, your problem and the answer is also the same as this topic.

"Problem with subsequent calls to WriteEp"
http://knowledgebase.nxp.com/showthread.php?t=4791

Tsuneo
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