I am looking at the usrp_std.v module and the schematics for the FPGA
the FX2/FPGA interface.
It seems to me that the data of course arrives as a serial input to the
chip. Then, it gets to the FPGA as a 16bit parallel input from the GPIF
That input is called usb_data in the FPGA. However, upon reading the
code of the serial_io.v module, it seems that this module does a serial
parallel conversion of the SDI input and puts it into the 32 bit
output register. I am confused as to whether the serial data from the
is converted to parallel in the FX2 chip or whether the data sent to
FPGA is serial but a verilog module inside the FPGA converts it to
parallel. So I am not sure whether the data coming from the USB to the
usrp_std.v module is the 16bit input usb_data or the SDI input.
Thank you ahed of time,