New uses of FPGAs

On 2019-07-08 snipped-for-privacy@gmail.com wrote in comp.arch.fpga:

In my experience FPGAs don't have very good optical properties, but YMMV.

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Stef    (remove caps, dashes and .invalid from e-mail address to reply by mail) 

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Altera had a prototype of FPGA with fiber connection to the silicon.

They are used in SFPs, eg

Are SFPs used for interfaces other than fiber? I see in Wikipedia that 1000 and 100BASE copper is supported. What about other such as T1/E1 or serial port circuits?

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  Rick C. 

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What do you think about PYNQ? Zynq can be used easily for machine learning.

SFPs are ethernet PHYs. There are PHYs for twisted pair (RJ45), and passive direct attach copper cables (SFP on each end). T1/E1 and serial ports aren't ethernet.

I suppose in principle someone could do a 10BASE2 or 10BASE5 SFP, but they don't seem to exist.

Theo

Pffft. SFPs, as defined by their SFF, are independent of Ethernet. The vast majority of SFPs are little more than a laser, a photodiode, amplifiers and a control/monitoring circuit. This makes them protocol agnostic, and they work quite well for any optical protocol, such as SONET or Fibrechannel within their bitrate range.

Some SFPs (they're in the minority) contain active electronics that will terminate Ethernet (in the form of SGMII, 1000Base-X or 10GBase-X) protocol on the electrical interface side, and convert it to something else. There are many "something elses". I've used ones that convert to: E1 DS3

1000Base-T N-Base-T 10GBase-T There are also SFPs that convert digital video to Ethernet. See this company for example:

Let's not forget Pasive DACs (Direct Attach Cables). These are basically two twinax cables with an SFP on each end (and also AC coupling caps, an EEPROM, but typically no microcontroller). The range is limited to a couple of meters or so at 10Gb/s, but they're the cheapest way to link equipment in a rack. Active DACs are like passive DACs but contain amplifiers, to attain more range (some meters).

Regards, Allan

I could be mistaken but I thought a colleague showed me a unit that brought in T1/E1. I could be mistaken.

10BASE2 and 10BASE5 are older technologies that are not so widely used. 10/100BASE-T is much more common and SFP units are available.

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  Rick C. 

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The company i mentioned do SFPs for SDI over copper, using mini-BNC or DIN connectors. The idea being that you can start off with cheap copper and transition to more expensive fibre. They also do SDI to HDMI SFPs.

Not so widely used? I'd dare say they are extinct. Of course one might actually find either used in the field, but it'll be a million-to-one find. Sort of like finding that Amiga still controlling the school's HVAC or whatever.

Average time of a T connector on a 10BASE2 networking flaking out was measured in months, it would be miraculous if you found a complete network working.

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Doug McIntyre 
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