FPGA

Comments

• Archiver Posts: 46,084

  2003-11-04 15:15 edited 2003-11-04 15:15

  Look at Al William's site -- excellent overview.
  
  All "Programmable Logic" chips allow you to
  implement a digital design of logic gates into
  a chip. When you do this you get a device
  which implements a state-machine, or a logic
  equation -- and can run much faster than the
  equivalent in a microprocessor.
  
  An FPGA differs from PLD or PAL in that typically
  in a PLD (like 22V10) you actually 'burn' fuses
  in the device -- the device itself holds the
  configuration.
  
  An FPGA typically has a MUCH larger 'sea-of-gates'
  to be connected. Some of the largest actually
  download their configuration from an attached
  EEPROM on power-up. Also, FPGA can be
  re-programmed in-circuit. Most PLD or PAL
  require a special programmer.
  
  It is suitable for combinatorial logic. For
  sequential logic, if you can design a
  state-machine implementation, you can put that
  into an FPGA.
  
  A "typical" small example often used is to
  build a traffic light control state-machine.
  Inputs are the car-sensors in the pavement,
  and a 'clock-tick'. Outputs are the Yellow-Red-
  Green light signals in all 4 directions.
  
  I've used them for communication capture.
  Some have DSP cores, and can give you fast
  fourier transforms in real-time (derive the
  frequency components of an input signal).
  Some FPGA's are big enough to implement your
  own microprocessor core inside. Some give
  you LOTS of I/O in a small package.
  
  Parallax sells 3 development boards supporting
  the Altera FPGA's. If your need for signal
  processing speed is not met by the 50 MIPS
  SX processor line, FPGA's give you a higher
  speed alternative.
  
  --- In basicstamps@yahoogroups.com, "basicstampede"
  <basicstampede@y...> wrote:
  > Guys,
  >
  > I know this is not the site for FPGA, but I don't know where else
  to
  > turn.
  >
  > I would like a short introduction to what FPGA is. How does it
  > differ from PLD or PAL?
  >
  > Is it suitable for combinatorial logic or sequential logic or both?
  >
  > Which of the offerings by Parallax do you recommend for a FPGA
  > beginner whose basic goal is to learn and get some hands on
  > experience?
  >
  > Can anyone give me an example of how to use an FPGA?
  >
  > I think I "know" what it is, but I want to make sure before I buy
  one.
  >
  >
  > Thanks for help.