From: Rainer Buchty (rainer_at_buchty.net)
Date: 2006-03-01 13:46:05
>Then there are also FPAAs which are FPGAs analog counterpart, good for >SID filter creation or VIC video creation. Actually, no. It would be completely nonsensical to use FPAAs for that. The FPAAs I've looked at were little more than programmable gain cells, so you could program some arbitrary, low level amplification and/or filtering, but that's about it. Any native OTA-based design is more flexible, and, for that matter, way more economical. That is why FPAAs have pretty much vanished from the market -- and I doubt that they will ever come back. Unlike logic equations, which you can map cheaply to lookup tables, storage elements, and routing, you can't really do a universal analog "FPGA" which would e.g. require to have programmable capacitors and resistors for instance. With the advent of enough computing power to do all in the digital domain, there's also no need for going analog anymore, check out software-defined radio for instance. >CPLDs are fuse programmable No, otherwise they wouldn't be reprogrammable anymore :) But they are manufactured in EEPROM or Flash technologies instead of SRAM. >Many of the vendor programs include schematic entry, which may be >easier if you are having trouble with learning the languages. I have >heard in the past that this is buggy, but that was years ago and this >may be much more stable by now. Noone is doing schematic entry anymore apart from maybe showing high-level connections between "black boxes". It's usually taking too much time, plus it also leads the designer to adopt "dirty" tricks from ancient time like building delays with a series of buffers/inverters. In addition, it doesn't really make sense to e.g. build some decoder circuit, state machines etc. the hard way by using many 74xx. Any VHDL or Verilog code would be way more readable and understandable in that respect. Rainer Message was sent through the cbm-hackers mailing list
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