Re: [Discuss-gnuradio] usrp: rssi/clipping indicator, data glitches

[Eric Blossom]

On Thu, Jan 04, 2007 at 04:31:39PM -0500, Don Ward wrote:
> 
> Questions:  Should we expect usrp register read requests to interfere with
> data transfers?  Is there a better way to access the rssi/clipping
> indicator?  Will mblocks allow internal USRP information (such as the rssi
> registers) to be included in data packets read from the USRP?

Until we switch to "in-band signaling", register read/writes are
handled using USB command packets which have higher priority than bulk
transfers.  They are are also implemented in the FX2 via relatively
slow bit-banging code.  While it's bit-banging, it's not forwarding
packets between the GPIF and the USB bus.  Given the small amount of
FIFO implemented in the FPGA, under/overruns are possible.

Eric