Quote Originally Posted by kirtcathey View Post
Have a very basic question that I want to confirm before going forward...

In the PBP manual, USBIN is described as:

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USBIN Endpoint, Buffer, Countvar, Label

Get any available USB data for the Endpoint and places it in the Buffer. Buffer must be a byte array of suitable length to contain the data. Countvar will contain the number of bytes transferred to the buffer. Label will be jumped to if no data is available.
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It was my understanding that with or without data, that this function always went to Label. Then within Label we perform a test to see if Buffer has new data and route execution from there.

However, the way that the PBP manual describes it is that if no data is input, then program execution jumps to Label.

Which one is it? Does this function always go to Label after reading 8 bytes (or however many specified during HID config. and specified in CountVar) even if there was or was not any input? Or, does this function only jump to Label when no bytes are read from the bus?
I have some of the same questions. What IS and endpoint anyway???


In my findings the above example from the manual is backwards. It will only jump to the label if the buffer is FULL. It seems to sit and wait until the specified number of bytes have been received.