Re: Advantages of running IOC on FPGA

[Pete Jemian via Tech-talk <tech-talk at aps.anl.gov>]

Isn't DMA a distinct advantage with running EPICS and FPGA on the same 
silicon?  Gives hardware-level access to data and allows for interrupts 
to the OS from the FPGA.

Pete
(The one who does not program FPGA, just listens to others.)

On 6/2/2021 10:49 AM, Till Straumann via Tech-talk wrote:
> Raj.
>
> Regarding network security: most facilities use firewalls and isolated 
> network segments
> for security.
> This is orthogonal to your question - EPICS is not particularly secure 
> (but neither is your
> proprietary UDP protocol going to be).
>
> Re. maintenance: yes, you will have to maintain EPICS on an additional 
> target platform.
> However, the zynq/arm target is well supported and I wouldn't expect any 
> particular
> problems. On the upside: you *only* have to support EPICS and won't have 
> to maintain/support
> your proprietary solution in addition to EPICS.
>
> Again: communicating with hardware and providing a standardized 
> networking interface
> (channel-access) is pretty much the definition of an IOC under EPICS.
>
> If IOC system load due to many clients is a concern then that is 
> traditionally mitigated with
> a channel-access gateway.
>
> HTH
> - Till
>
>
> On 6/1/21 11:17 PM, Kunjir, Shriraj wrote:
> > Hi Till,
> >
> > Thank you for your response. Could you please elaborate on the 
> > maintenance and network security aspect of such an LLRF controller 
> > when it runs IOC on its PS side Linux?
> >
> > We are evaluating the potential of running IOC on our Zynq based LLRF 
> > controllers.
> >
> > *From: *Till Straumann via Tech-talk <mailto:tech-talk at aps.anl.gov>
> > *Sent: *Tuesday, June 1, 2021 5:09 PM
> > *To: *tech-talk at aps.anl.gov <mailto:tech-talk at aps.anl.gov>
> > *Subject: *Re: Advantages of running IOC on FPGA
> >
> > *[EXTERNAL] This email originated from outside of FRIB*
> >
> > I'd say that the 'traditionally' an IOC *is* actually executed on a 
> > front-end controller
> > with EPICS taking care of networking and control-system integration. 
> > This is what
> > EPICS was originally designed for. (IOCs running on embedded VME 
> > computer that
> > were directly talking to hardware).
> >
> > When you don't run an IOC on the Zynq then you have to invent your 
> > proprietary
> > UDP protocol, write some sort of server that does I/O on the Zynq and 
> > some protocol
> > translation to EPICS on the 'IOC server'.
> >
> > FPGA <-> ZYNQ (I/O -> UDP) <-> ethernet <-> server (UDP -> EPICS)
> >
> > You can eliminate all this effort simply by running an IOC on the zynq.
> >
> > Cheers
> > - Till
> >
> >
> > On 6/1/21 10:14 PM, Kunjir, Shriraj via Tech-talk wrote:
> > > Hello,
> > >
> > > Could you please help in understanding the advantages of running IOC 
> > > server on LLRF Zynq FPGA over the traditional method of a standalone 
> > > IOC server connecting to LLRF FPGA via UDP. Thank you
> > >
> > > Raj

--
----------------------------------------------------------
Pete R. Jemian, Ph.D.                 <jemian at anl.gov>
Beam line Controls and Data Acquisition (BC, aka BCDA)
Advanced Photon Source,    Argonne National Laboratory
Argonne, IL  60439                    630 - 252 - 3189
-----------------------------------------------------------
      Education is the one thing for which people
         are willing to pay yet not receive.
-----------------------------------------------------------