> Don't forget that they are reprogrammable, so they are upgradeable. Some
> designs may need updates or functionality changes after deployment, and
> some may need to be reconfigured regularly.
>=20
> If you use an ASIC, you are stuck with the initial design.

Some FPGAs are reprogrammable, some are one time program. Some boot up of a=
n external serial EEPROM every time they are powered up, to download the pr=
ogramming into the FPGA.

> 3. Why are they used?

Another reason I haven't seen in an answer yet (but I haven't yet read them=
 all) is to keep IP secret. This is probably more of a concern for complex =
things like encryption methods, e.g. encrypted video, where the whole proce=
ss can be hidden inside the chip. Some manufacturers make FPGA chips where =
the programming cannot be revealed by taking the lid off and shaving the va=
rious layers to get the mask patterns. Whatever changes during programming =
isn't easily revealed by this method.
--=20
Scanned by iCritical.

--=20
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