LPC1347: Help with Firmware Update with IAP Command 57

Discussion created by lpcware Employee on Jun 15, 2016
Latest reply on Jun 15, 2016 by lpcware
Content originally posted in LPCWare by BPC on Fri Jun 06 09:28:18 MST 2014

I am using the LPC1347 as a CDC device.  To update firmware, I have implemented IAP / ISP Command 57 to reset the device as a Mass Storage Device.  This works very well and I can repeat the process over and over (i.e. 100 times) without any reliability issues.

I have recently observed a situation where I let the board run in CDC mode for a long period of time (i.e. 24 hours) and then call the firmware update command.  In this situation, the board does not reconnect as a Mass Storage Device.  The USB_CONNNECT line does not activate which I can see by the absence of the LED illumination in the USB Soft Connect implementation.  After the WDT resets the board (even though no firmware was update), I simply issue the command a second time and it works perfectly.

Does anyone know what could cause this behavior? 

Thank you.