search

enjoy-digital / litex_m2sdr

LiteX based M2 SDR FPGA board.
BSD 2-Clause "Simplified" License
67 stars 7 forks source link

Switch PCIe Data-Width to 128-bit? #17

Closed enjoy-digital closed 5 months ago

enjoy-digital commented 5 months ago

Maximum throughput on the RFIC (without Oversampling) with 12->16 bit packing is 64-bit * 61.44e6 = 3932Mbps.

With the PCie at 64-bit @ 125MHz, we should already have ~8000Mbps in X4 case. We should have enough margin but this could be useful to see if switching to 128-bit bus would be interesting.

If additional DMAs are added to allow internal processing/filtering and stream it over the additional DMA, extra throughput will be welcome.

enjoy-digital commented 5 months ago

Will not be required since 122.88MSPS 2T2R is running fine with 64-bit @ 125MHz. Additional processing/filtering modules will use an additional DMA do 64-bit data-width on DMA0 will not be a bottleneck.