21-09-2013, 03:51 PM
Introduction to Programmable Logic Devices
Programmable Logic.ppt (Size: 671.5 KB / Downloads: 47)
Introduction
Comparison of Standard Logic Circuits
and Programmable Logic Circuits
Evolution and Overview of PLC:
PROM, PLA, PAL
CPLD
FPGA
Standard Logic Circuits
Appropriate for many applications because of possibility of realization in mass production for relative low cost.
Standard logic circuits are sometimes the best choice
in high-performance devices.
Disadvantage:
Not permitting design updates (function changes)
with no hardware replacement necessary.
Field- Programmable Logic Devices
Component function is defined by users program.
Logic Cells Fields are interconnected by programming.
Advantages:
Flexible design that changes by reprogramming, ease of design changes
Reduce prototype-product time
Large scale integration (over 100 000 gates)
Reliability increased, low financial risk
Smaller device, low start-up cost
Evolution of PLD: FPGA
Difficult extending CPLDs architectures to higher densities -
a different approach is needed
FPGAs comprise an array of uncommited circuit elements,
called logic blocks, and interconnect resources
FPGA configuration is performed through
programming by the end user.