8-bit wire format?

Projects LimeSDR
1

Does the Lime family currently support 8-bit over-the-wire samples?

Just getting back to using some LimeSDRs in the lab at CCERA, and also have a pair of
LimeSDR-minis on-order for a pulsar project.

I’m currently playing with one of the 3 Odroid-HC1 units I have lying around the lab,
since I can plug in a SATA drive, and Pulsar Filterbank data are “chunky”. But the HC1
only has a USB-2.0 port on it, and it’s not that capacious. So, looking for ways to reduce
the over-the-wire traffic while supporting bandwidths up to 10Msps.

2

For the LimeSDR-USB I’ve only seen support for the transfer of 12-bit, 14-bit and 16-bit samples across the USB bus for RX and TX ( https://github.com/myriadrf/LimeSDR-USB_GW/blob/master/src/rx_packets/compress_v2.vhd and https://github.com/myriadrf/LimeSDR-USB_GW/blob/master/src/data_manipulation/decompress.vhd ).

And the same is true for the LimeSDR-mini ( https://github.com/myriadrf/LimeSDR-Mini_GW/blob/master/LimeSDR-Mini_lms7_trx/src/rx_path_top/bit_pack/synth/bit_pack.vhd and https://github.com/myriadrf/LimeSDR-Mini_GW/blob/master/LimeSDR-Mini_lms7_trx/src/tx_path_top/bit_unpack/synth/unpack_64_to_48.vhd ; https://github.com/myriadrf/LimeSDR-Mini_GW/blob/master/LimeSDR-Mini_lms7_trx/src/tx_path_top/bit_unpack/synth/unpack_64_to_56.vhd ; https://github.com/myriadrf/LimeSDR-Mini_GW/blob/master/LimeSDR-Mini_lms7_trx/src/tx_path_top/bit_unpack/synth/unpack_64_to_64.vhd )

So in my mind the answer would be that there is no current support for 8-bit over the wire samples. For that you would need to throw away 4 bits and then the question becomes which do you choose the top nibble or the bottom nibble to discard.