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Re: [Discuss-gnuradio] usrp: rssi/clipping indicator, data glitches
From: |
Eric Blossom |
Subject: |
Re: [Discuss-gnuradio] usrp: rssi/clipping indicator, data glitches |
Date: |
Fri, 5 Jan 2007 11:26:43 -0800 |
User-agent: |
Mutt/1.5.9i |
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