<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div>Hi Gerard,</div></div></span><br class="Apple-interchange-newline"></div></span>David put together a draft document for the current spec - <a href="http://argus.phys.uregina.ca/cgi-bin/private/DocDB/ShowDocument?docid=2274">http://argus.phys.uregina.ca/cgi-bin/private/DocDB/ShowDocument?docid=2274</a><br class="Apple-interchange-newline"></span><br class="Apple-interchange-newline">
</div><div>There the slot does come before the channel, and we have one large 15-bit chunk designated as quality factor which would include the pedestal.</div><div>I hadn't realized that the slot would also be in the block header. </div><div><br></div><div>Could we take some of the 5 bits marked slot and move them into the QF section? The extra space (QF would then be 20 bits) would allow for full precision pedestal in 12 bits, plus another 8 for quality indicators. Also, we have 3 bits in the block header to designate data format, or rather, how to interpret the QF part. I would hope that we would not go through more than 8 iterations of this but it could happen, and 1 or 2 bits of the QF section could be kept aside for this. If we have full precision pedestal in the event readout then I don't think we would need separate pedestal runs. </div><div><br></div><div>(Is there another header designating the crate which is tagged on separately?)</div><div><br></div><div>Best, </div><div><br></div><div>Naomi.</div><div><br></div><div><br></div><div><br class="webkit-block-placeholder"></div>
<br><div><div>On Jul 23, 2013, at 9:58 AM, Gerard Visser wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div>hi Dave,<br><span class="Apple-tab-span" style="white-space:pre"> </span>I think it might be better to provide a more generic and all-encompassing <br>redundancy in the data, such as by inserting a CRC word every N hits or at end <br>of block or something like that. Just a fixed pattern on a few bits is a pretty <br>minimalist sort of redundancy, e.g. would not detect if an even number of <br>longwords was dropped, for instance.<br><span class="Apple-tab-span" style="white-space:pre"> </span>I also suspect that more bits might be good for quality/status of the hit, <br>although I don't have a specific proposal. At the moment I see it is proposed <br>(1c) to have 13 bits for "pedestal"&quality (these are all quality bits IMHO). <br>This may eventually prove not to be enough, then the 5 slot bits could be added <br>into this purpose.<br><span class="Apple-tab-span" style="white-space:pre"> </span>Regardless of the slot bits, I think you are certainly right to put some <br>redundancy in the data that can be used for integrity check, so IMHO you should <br>add some CRC words explicitly for that purpose.<br><span class="Apple-tab-span" style="white-space:pre"> </span>Sincerely,<br><br><span class="Apple-tab-span" style="white-space:pre"> </span><span class="Apple-tab-span" style="white-space:pre"> </span>Gerard<br><br>p.s. Minor point: If you do keep slot field, how about putting it to the left of <br>channel field, so that the whole thing can be interpreted as a 12 bit <br>superchannel number? Of course the bit arrangement doesn't matter except to <br>improve human readability of the code and data.<br><br><br>On 7/23/2013 1:14 AM, David Lawrence wrote:<br><blockquote type="cite"><br></blockquote><blockquote type="cite">Hi Gerard,<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite"> That's correct, "slot" is the slot in the VME crate. You're right, it<br></blockquote><blockquote type="cite">could be sacrificed from the hit record if needed. Right now, it appears<br></blockquote><blockquote type="cite">in the both the block header and hit record and is currently used by the<br></blockquote><blockquote type="cite">parsing software to provide a small integrity check on the data. If<br></blockquote><blockquote type="cite">there is something else more worthy of those bits, we can consider<br></blockquote><blockquote type="cite">dropping it from the hit record.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Regards,<br></blockquote><blockquote type="cite">-Dave<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">On 7/23/13 12:47 AM, Gerard Visser wrote:<br></blockquote><blockquote type="cite"><blockquote type="cite">hi Naomi, Dave,<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><span class="Apple-tab-span" style="white-space:pre"> </span>What is 'slot' by the way? (5/62 hit payload bits used for this.) I guess it is<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">the ADC module number? But why put this in the hit record? It can just as well<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">be in the block or event header from the module, it will be constant for all hit<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">records from the module...<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><span class="Apple-tab-span" style="white-space:pre"> </span>- Gerard<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">On 7/22/2013 7:58 PM, Naomi Jarvis wrote:<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite">Minutes are online at <a href="https://halldweb1.jlab.org/wiki/index.php/July_17,_2013_Tracking_CDC/FDC">https://halldweb1.jlab.org/wiki/index.php/July_17,_2013_Tracking_CDC/FDC</a><br></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite">Also I think I forgot to email the same for the previous meeting, sorry, those are at <a href="https://halldweb1.jlab.org/wiki/index.php/July_3,_2013_Tracking_CDC/FDC">https://halldweb1.jlab.org/wiki/index.php/July_3,_2013_Tracking_CDC/FDC</a><br></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite">Best regards,<br></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite">Naomi.<br></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">_______________________________________________<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">Halld-tracking-hw mailing list<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><a href="mailto:Halld-tracking-hw@jlab.org">Halld-tracking-hw@jlab.org</a><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><a href="https://mailman.jlab.org/mailman/listinfo/halld-tracking-hw">https://mailman.jlab.org/mailman/listinfo/halld-tracking-hw</a><br></blockquote></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">_______________________________________________<br></blockquote><blockquote type="cite">Halld-tracking-hw mailing list<br></blockquote><blockquote type="cite"><a href="mailto:Halld-tracking-hw@jlab.org">Halld-tracking-hw@jlab.org</a><br></blockquote><blockquote type="cite"><a href="https://mailman.jlab.org/mailman/listinfo/halld-tracking-hw">https://mailman.jlab.org/mailman/listinfo/halld-tracking-hw</a><br></blockquote><blockquote type="cite"><br></blockquote>_______________________________________________<br>Halld-tracking-hw mailing list<br><a href="mailto:Halld-tracking-hw@jlab.org">Halld-tracking-hw@jlab.org</a><br>https://mailman.jlab.org/mailman/listinfo/halld-tracking-hw<br></div></blockquote></div><br></body></html>