Hello, I am looking at the toplevel module ustp_std.v It is my understanding that the data to be sent coming from the PC or the data recevied going to the PC is the "usbdata" inout. the other inouts io_tx_a, io_tx_b, io_rx_a and io_rx_b are the signal going to/coming from the daughterboards.
I am still confused on the purpose of the following inputs: rx_a_a, rx_b_a, rx_a_b, rx_b_b and the following outputs: tx_a, tx_b.
Any clarification on the purpose of those inputs and outputs would me greatly appreciated.