> any objections to supporting only the RTIO clock frequency (currently 150MHz) > at the Sayma input, instead of 100MHz?
Assuming you mean "supporting" in the sense of which bitstreams M-Labs will build and test, I'm fine with that. IIRC, changing reference frequency is pretty easy and only requires changing HMC830 divider values (https://github.com/m-labs/artiq/blob/574892a4e549e5882a46dcfa51016f5051404869/artiq/firmware/libboard_artiq/hmc830_7043.rs#L336) and potentially the FPGA SYSREF phase to meet S/H (https://github.com/m-labs/artiq/blob/574892a4e549e5882a46dcfa51016f5051404869/artiq/firmware/libboard_artiq/hmc830_7043.rs#L175) -- and that latter requirement could probably be removed by adding a proper CDC on that input. So it's easy for users to change this later on to whatever they want (within reason). > I think it is more easy way to leave an 10MHz clock input, through I don't > understand why almost all of the frequency standard output 10MHz. I don't think that's supported in HW atm (baluns etc). You'd have to check. In any case, the design is optimized for working with a higher frequency reference than 10MHz. You'll take a bit of a phase noise hit if you try to use the HMC830 to get from 10MHz to 2GHz. T Dr Thomas Harty Junior Research Fellow, St John's College University of Oxford, Department of Physics The Clarendon Laboratory Parks Road, Oxford, OX1 3PU Mob: +44 (0)7986 375 052 Lab: +44 (0)1865 272 572 ________________________________ From: ARTIQ <artiq-boun...@lists.m-labs.hk> on behalf of artiq-requ...@lists.m-labs.hk <artiq-requ...@lists.m-labs.hk> Sent: 19 June 2018 11:00:07 To: artiq@lists.m-labs.hk Subject: ARTIQ Digest, Vol 49, Issue 2 Send ARTIQ mailing list submissions to artiq@lists.m-labs.hk To subscribe or unsubscribe via the World Wide Web, visit https://ssl.serverraum.org/lists/listinfo/artiq or, via email, send a message with subject or body 'help' to artiq-requ...@lists.m-labs.hk You can reach the person managing the list at artiq-ow...@lists.m-labs.hk When replying, please edit your Subject line so it is more specific than "Re: Contents of ARTIQ digest..." Today's Topics: 1. Sayma input frequency (Sébastien Bourdeauducq) 2. Re: Sayma input frequency (Slichter, Daniel H. (Fed)) 3. Re: Sayma input frequency (joe wong) ---------------------------------------------------------------------- Message: 1 Date: Mon, 18 Jun 2018 21:28:55 +0800 From: Sébastien Bourdeauducq <s...@m-labs.hk> To: "artiq@lists.m-labs.hk" <artiq@lists.m-labs.hk> Cc: Ken Brown <ken.br...@chemistry.gatech.edu>, Jungsang Kim <jungs...@duke.edu> Subject: [ARTIQ] Sayma input frequency Message-ID: <a4841630-5e3c-8c56-4c4a-beb6f86c8...@m-labs.hk> Content-Type: text/plain; charset=utf-8; format=flowed Hi, any objections to supporting only the RTIO clock frequency (currently 150MHz) at the Sayma input, instead of 100MHz? Are you using non-programmable 100MHz references? Sébastien ------------------------------ Message: 2 Date: Mon, 18 Jun 2018 21:27:19 +0000 From: "Slichter, Daniel H. (Fed)" <daniel.slich...@nist.gov> To: Sébastien Bourdeauducq <s...@m-labs.hk>, "artiq@lists.m-labs.hk" <artiq@lists.m-labs.hk> Cc: Ken Brown <ken.br...@chemistry.gatech.edu>, Jungsang Kim <jungs...@duke.edu> Subject: Re: [ARTIQ] Sayma input frequency Message-ID: <sn1pr09mb0847a2c6edeee4c14aef7a7291...@sn1pr09mb0847.namprd09.prod.outlook.com> Content-Type: text/plain; charset="utf-8" It is certainly possible to get nice low-phase-noise sources at 150 MHz instead of 100 MHz, but these would need to be special ordered. How much of a challenge is using 100 MHz? Does the HMC830 not allow us leeway here? One temporary solution would be to use an HMC830 (or equivalent) eval board to generate 150 MHz from another reference frequency and feed that to the Sayma input connector. However, over the longer term I think it would be good to have Sayma able to operate from a more standard reference frequency such as 100 MHz. > -----Original Message----- > From: ARTIQ [mailto:artiq-boun...@lists.m-labs.hk] On Behalf Of Sébastien > Bourdeauducq via ARTIQ > Sent: Monday, June 18, 2018 7:29 AM > To: artiq@lists.m-labs.hk > Cc: Ken Brown <ken.br...@chemistry.gatech.edu>; Jungsang Kim > <jungs...@duke.edu> > Subject: [ARTIQ] Sayma input frequency > > Hi, > > any objections to supporting only the RTIO clock frequency (currently > 150MHz) at the Sayma input, instead of 100MHz? > Are you using non-programmable 100MHz references? > > Sébastien > _______________________________________________ > ARTIQ mailing list > https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fssl.serverr > aum.org%2Flists%2Flistinfo%2Fartiq&data=02%7C01%7Cdaniel.slichter%40nist. > gov%7C05f9ee8fb8ec4fc6878308d5d51f7c2f%7C2ab5d82fd8fa4797a93e054655 > c61dec%7C1%7C0%7C636649253558496201&sdata=tfd6NTpKq73oYUwH3t7J9 > w%2FUOnfF0IhOAa8ksKkYzB8%3D&reserved=0 ------------------------------ Message: 3 Date: Tue, 19 Jun 2018 10:35:29 +0800 From: joe wong <joeshar...@gmail.com> To: "Slichter, Daniel H. (Fed)" <daniel.slich...@nist.gov> Cc: Sébastien Bourdeauducq <s...@m-labs.hk>, "artiq@lists.m-labs.hk" <artiq@lists.m-labs.hk>, Ken Brown <ken.br...@chemistry.gatech.edu>, Jungsang Kim <jungs...@duke.edu> Subject: Re: [ARTIQ] Sayma input frequency Message-ID: <cajnqb6sf4v+e0idzr3aovcxfk+afe_4cmzy3ilueim+bsez...@mail.gmail.com> Content-Type: text/plain; charset="utf-8" Hi All, the frequency standard output generally 10MHz, many choices like SRS FS725 or FS740. Usually, they need the GPS to calibrate 1pps signal. I think it is more easy way to leave an 10MHz clock input, through I don't understand why almost all of the frequency standard output 10MHz. Best On Tue, Jun 19, 2018 at 10:01 AM Slichter, Daniel H. (Fed) via ARTIQ < artiq@lists.m-labs.hk> wrote: > It is certainly possible to get nice low-phase-noise sources at 150 MHz > instead of 100 MHz, but these would need to be special ordered. How much > of a challenge is using 100 MHz? Does the HMC830 not allow us leeway > here? > > One temporary solution would be to use an HMC830 (or equivalent) eval > board to generate 150 MHz from another reference frequency and feed that to > the Sayma input connector. However, over the longer term I think it would > be good to have Sayma able to operate from a more standard reference > frequency such as 100 MHz. > > > -----Original Message----- > > From: ARTIQ [mailto:artiq-boun...@lists.m-labs.hk] On Behalf Of > Sébastien > > Bourdeauducq via ARTIQ > > Sent: Monday, June 18, 2018 7:29 AM > > To: artiq@lists.m-labs.hk > > Cc: Ken Brown <ken.br...@chemistry.gatech.edu>; Jungsang Kim > > <jungs...@duke.edu> > > Subject: [ARTIQ] Sayma input frequency > > > > Hi, > > > > any objections to supporting only the RTIO clock frequency (currently > > 150MHz) at the Sayma input, instead of 100MHz? > > Are you using non-programmable 100MHz references? > > > > Sébastien > > _______________________________________________ > > ARTIQ mailing list > > > https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fssl.serverr > > aum.org > %2Flists%2Flistinfo%2Fartiq&data=02%7C01%7Cdaniel.slichter%40nist. > > gov%7C05f9ee8fb8ec4fc6878308d5d51f7c2f%7C2ab5d82fd8fa4797a93e054655 > > c61dec%7C1%7C0%7C636649253558496201&sdata=tfd6NTpKq73oYUwH3t7J9 > > w%2FUOnfF0IhOAa8ksKkYzB8%3D&reserved=0 > _______________________________________________ > ARTIQ mailing list > https://ssl.serverraum.org/lists/listinfo/artiq > -------------- next part -------------- An HTML attachment was scrubbed... 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