6 ms·

What kind of applications are these very low cost, low gate, FPGAs used for?

guerrilla 5y ago
Not an EE but I know exactly what I'm going to use these for: Playing with old CPUs so that I can implement all the bus and decode logic and some peripherals in it. Something like this[1] but even simpler. They'll probably be used for similar but more realistic stuff, i.e. as reconfigurable glue. 1. http://www.mattmillman.com/projects/8od/ http://www.mattmillman.com/projects/8od/
- d_tr 5y ago
  Why not simply get one of the many cheap development boards that are available right now and with much larger FPGAs instead of waiting an unspecified amount of time for these? These devices are painfully small for something like this and it is not clear whether they have any hard adders and multipliers.
  - guerrilla 5y ago
    yosys and minimalism mainly. As a hobbyist, I like to work with as little as I can get away with for fun and art. I think professionals will be more interested because of the price.
    - d_tr 5y ago
      Fair enough!
CyberRabbi 5y ago
Probably custom high speed interconnect or glue logic that cheap MCUs cannot do. This is in relatively high demand given the current chip shortage. If this can do in-circuit programming, it’s huge.
londons_explore 5y ago
Hooking up two otherwise incompatible busses. For example, say you want to connect an SPI flash device to something that only supports NAND flash - you might use one of these FPGA's to act as a kind of converter.
deleted 5y ago
[deleted]
ncmncm 5y ago
And, what rate can you clock them at? You can use these to replace a microcontroller doing a simple job it was not fast enough for, or burned too much power for, or you can't buy any of just now. It feels funny to write this, because we used to say you could put a microcontroller in, in place of custom logic if it was fast enough. The best 6502 project I have seen put an 80MHz microcontroller on a 40-pin DIP format board, that bit-bangs out a 6502 on the pins. It has enough RAM to copy 64k in and execute from, where timing isn't critical.
- jacquesm 5y ago
  That sounds like a fun project.
  - linker3000 5y ago
    Here's a Z80 variant: https://j4f.info/z80-mbc2 https://j4f.info/z80-mbc2 Fabio has also done boards for the NEC V20 and 68K
    - jacquesm 5y ago
      What a clean design. I wished my 'daily driver' had such easy interface options for hardware.
- snvzz 5y ago
  >And, what rate can you clock them at? High occupation projects on iCE40 LP1K (closest thing) easily clock 70-100MHz in my experience.
  - ncmncm 5y ago
    We can guess, but that seems pointless.
lnsru 5y ago
Look at Lattice’s marketing material. They have tons of applications covered. Mostly protocol converters, level shifters, all sort of glue logic, gate drivers an so on.
phire 5y ago
One real world example: The pebble time used a small FPGA to act as a display controller for their custom ePaper-like color LCD display. Allowed them to interface with the non-standard display on a cheap off the shelf microcontroller, without having to waste power bitbanging. As a bonus, the bitstream also included the startup splash screen which would show instantly, before the cpu even got around to initializing the display controller.
- desdiv 5y ago
  >The pebble time used a small FPGA to act as a display controller for their custom ePaper-like color LCD display. Minor correction: the pebble time uses a standard off-the-shelf Sharp Memory LCD display[0]. These displays are commonly used on smart watches so they're not propriety to Pebble. Sharp ships these displays as complete modules, with all control logic built-in, so you just need to supply power and serial commands to drive them. Any standard microcontroller can drive these. You're right that Pebble chose to put an FPGA between their main microcontroller and the Sharp Memory LCD though. [0] https://www.sharpmemorylcd.com/ https://www.sharpmemorylcd.com/

Not an EE but I know exactly what I'm going to use these for: Playing with old CPUs so that I can implement all the bus and decode logic and some peripherals in it. Something like this[1] but even simpler. They'll probably be used for similar but more realistic stuff, i.e. as reconfigurable glue. 1. http://www.mattmillman.com/projects/8od/ http://www.mattmillman.com/projects/8od/

d_tr 5y ago
Why not simply get one of the many cheap development boards that are available right now and with much larger FPGAs instead of waiting an unspecified amount of time for these? These devices are painfully small for something like this and it is not clear whether they have any hard adders and multipliers.
- guerrilla 5y ago
  yosys and minimalism mainly. As a hobbyist, I like to work with as little as I can get away with for fun and art. I think professionals will be more interested because of the price.
  - d_tr 5y ago
    Fair enough!

CyberRabbi 5y ago

Probably custom high speed interconnect or glue logic that cheap MCUs cannot do. This is in relatively high demand given the current chip shortage. If this can do in-circuit programming, it’s huge.

londons_explore 5y ago

Hooking up two otherwise incompatible busses. For example, say you want to connect an SPI flash device to something that only supports NAND flash - you might use one of these FPGA's to act as a kind of converter.

deleted 5y ago

[deleted]

ncmncm 5y ago

And, what rate can you clock them at? You can use these to replace a microcontroller doing a simple job it was not fast enough for, or burned too much power for, or you can't buy any of just now. It feels funny to write this, because we used to say you could put a microcontroller in, in place of custom logic if it was fast enough. The best 6502 project I have seen put an 80MHz microcontroller on a 40-pin DIP format board, that bit-bangs out a 6502 on the pins. It has enough RAM to copy 64k in and execute from, where timing isn't critical.

jacquesm 5y ago
That sounds like a fun project.
- linker3000 5y ago
  Here's a Z80 variant: https://j4f.info/z80-mbc2 https://j4f.info/z80-mbc2 Fabio has also done boards for the NEC V20 and 68K
  - jacquesm 5y ago
    What a clean design. I wished my 'daily driver' had such easy interface options for hardware.
snvzz 5y ago
>And, what rate can you clock them at? High occupation projects on iCE40 LP1K (closest thing) easily clock 70-100MHz in my experience.
- ncmncm 5y ago
  We can guess, but that seems pointless.

lnsru 5y ago

Look at Lattice’s marketing material. They have tons of applications covered. Mostly protocol converters, level shifters, all sort of glue logic, gate drivers an so on.

phire 5y ago

One real world example: The pebble time used a small FPGA to act as a display controller for their custom ePaper-like color LCD display. Allowed them to interface with the non-standard display on a cheap off the shelf microcontroller, without having to waste power bitbanging. As a bonus, the bitstream also included the startup splash screen which would show instantly, before the cpu even got around to initializing the display controller.

desdiv 5y ago
>The pebble time used a small FPGA to act as a display controller for their custom ePaper-like color LCD display. Minor correction: the pebble time uses a standard off-the-shelf Sharp Memory LCD display[0]. These displays are commonly used on smart watches so they're not propriety to Pebble. Sharp ships these displays as complete modules, with all control logic built-in, so you just need to supply power and serial commands to drive them. Any standard microcontroller can drive these. You're right that Pebble chose to put an FPGA between their main microcontroller and the Sharp Memory LCD though. [0] https://www.sharpmemorylcd.com/ https://www.sharpmemorylcd.com/