Re: [time-nuts] Performance of TDC7200
Hi Thanks for the info. The fpga baesed TDC is something I am interested in. However, I am a beginner of fpga programming. Maybe next year I will spend sometime study this project. VHDL is quite difficult for a C programmer :(. Regards Li Ang BI7LNQ ---Original--- From: "Attila Kinali"<att...@kinali.ch> Date: 2016/12/16 02:00:32 To: "Discussion of precise time and frequency measurement"<time-nuts@febo.com>; Subject: Re: [time-nuts] Performance of TDC7200 On Fri, 9 Dec 2016 21:29:34 +0800 "Li Ang" <379...@qq.com> wrote: > I've done some tests with TDC7200 and TDC_GP22 few months > ago.(https://www.febo.com/pipermail/time-nuts/2016-May/098170.html) Thanks for the report. It's interesting to see that the TDC7200 performs slightly better than the GP22. BTW: If you are using a large FPGA like the EP4CE22, then you might want to consider using it directly as a TDC. You can fit four ring oscillator based TDC easily and have more than enough space for your control logic (we did a 4 TDC system with an NIOS2 core and some glue and still had space spare). The bin with is in the order of 22ps, with excursions up to 100ps. The code we used was based on the tdc-core by CERN[1] and can be found on my git server [2]. Special thanks to Florian Huemer who got it working properly. Attila Kinali [1] http://www.ohwr.org/projects/tdc-core/wiki [2] http://git.kinali.ch/attila/nios2_clocksync/tree/master/fpga/cores/tdc -- It is upon moral qualities that a society is ultimately founded. All the prosperity and technological sophistication in the world is of no use without that foundation. -- Miss Matheson, The Diamond Age, Neil Stephenson ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Performance of TDC7200
On Fri, 9 Dec 2016 21:29:34 +0800 "Li Ang" <379...@qq.com> wrote: > I've done some tests with TDC7200 and TDC_GP22 few months > ago.(https://www.febo.com/pipermail/time-nuts/2016-May/098170.html) Thanks for the report. It's interesting to see that the TDC7200 performs slightly better than the GP22. BTW: If you are using a large FPGA like the EP4CE22, then you might want to consider using it directly as a TDC. You can fit four ring oscillator based TDC easily and have more than enough space for your control logic (we did a 4 TDC system with an NIOS2 core and some glue and still had space spare). The bin with is in the order of 22ps, with excursions up to 100ps. The code we used was based on the tdc-core by CERN[1] and can be found on my git server [2]. Special thanks to Florian Huemer who got it working properly. Attila Kinali [1] http://www.ohwr.org/projects/tdc-core/wiki [2] http://git.kinali.ch/attila/nios2_clocksync/tree/master/fpga/cores/tdc -- It is upon moral qualities that a society is ultimately founded. All the prosperity and technological sophistication in the world is of no use without that foundation. -- Miss Matheson, The Diamond Age, Neil Stephenson ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Performance of TDC7200
I've done some tests with TDC7200 and TDC_GP22 few months ago.(https://www.febo.com/pipermail/time-nuts/2016-May/098170.html) Here is the performance test of my recent board. http://www.qsl.net/b/bi7lnq/Projects/freqcnt6.0/schematic.pdf http://www.qsl.net/b/bi7lnq/Projects/freqcnt6.0/freqcntv6.0.jpg The "analog front end" is 74lvc1g04/nc7sz125. 3 TDC7200s are on the board. Only TI mode is tested at the moment.(the truth is I forgot to connect the SPI port to FPGA .., I need to reuse the config ports to implement a bidirectional SPI to read the counters in FPGA) DUT and REF are from a homebrew distribution amp( http://www.qsl.net/b/bi7lnq/distribution_amp/v1.5/10M_distributor.pdf), the source is a FE180 OCXO. 1) the noise of 74LVC and NC7 are different. 2) the performance of my counter in TI mode is almost the same as the Agilent 53220A http://www.qsl.net/b/bi7lnq/Projects/freqcnt6.0/data/20161209/nc7sz125_74lvc1g04_53220a.png I also tried to measure 3 OCXOs at the same time. FE180, OCXO8663, free running TBOLT http://www.qsl.net/b/bi7lnq/Projects/freqcnt6.0/data/20161209/freqcnt_v6_20161209.png http://www.qsl.net/b/bi7lnq/Projects/freqcnt6.0/data/20161209/freqcnt_v6_20161209_3corneredhat.png TODO list: 1) web based interface, calculate and show *DEVs with javascript on Chrome browser 2) front end experiments Regards Li Ang / BI7LNQ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
