USB Transaction Time


#1

Hi,

I was wondering:
How long does it actual take for an USB Transaction to complete?
How much time does e.g. a “read WireOut” take?
How long is the PC blocked by this transaction?

Regards,
cdr


#2

Most of these are about 1ms. If you run a loop that just performs UpdateWireOuts(), you’ll get 1000/sec. This is due to OS-enforced restrictions on how many transactions can consume the USB.


#3

Actually, the PC is NOT blocked. The thread performing the call is.
You can use 2 threads with the one dedicated to XEM I/F being more prioritary than the other.


#4

That’s true. I should have clarified this point.