Approximate Equivalent Densities The Lattice GAL22V10 (a popular SPLD) is equivalent to about 500 logic gates. A typical Altera MAX7000 CPLD is equivalent to about 2500 logic gates. A typical Altera Cyclone FPGA is equivalent to about 50,000 gates.
Major PLD Manufacturers Three big names in this field are Xilinx, with 51% of market share Altera, with 34% Lattice, with less than 10% Market share numbers retrieved from Wikipedia on 9/10/2014.Wikipedia
Some Product Lines from Altera and Xilinx Altera CPLDs: MAX FPGAs: Cyclone, Arria, Stratix Programming software: Quartus II Xilinx: CPLDs: CoolRunner, XC9500 FPGAs: Vertix, Spartan, Kintex, Artix Programming software: ISE
FPGAs compared to CPLDs CPLDsFPGAs Based on programmable AND array and fixed OR array. Based on look-up table (LUT), which is basically a truth table. (Results in higher density.) Both are programmed using the same software, using either schematic entry or text entry.
Our Software and Equipment Software: Altera’s Quartus II, version 13.0 sp1. (Free download, so you can install it at home.)Free download Hardware: Altera Cyclone IV FPGA. Chip is mounted on Altera’s DE2-115 experimenter’s board. (Manual on course website.)Manual
Three Ways of Representing a Digital Circuit We have at least three ways of describing a digital circuit: 1. Diagram showing the logic gates. 2. Boolean expression. 3. Truth table. Given any one of these, you should be able to write the other two. See examples on following slides.
From Gate Diagram to Boolean Expression or Truth Table Given a gate diagram, you should be able to: 1. Write a Boolean expression for the diagram. 2. Write the truth table for the diagram. Example: Write a Boolean expression and the truth table for the following gate diagram.
From Boolean Expression to Gate Diagram or Truth Table Given a Boolean expression, you should be able to: 1. Draw a gate diagram that implements the expression. 2. Write the truth table for the expression. In many cases your job will be easier if you first use Boolean algebra or a Karnaugh map to simplify the expression. We’ll study these techniques next week. Example: Draw a gate diagram and write the truth table for X = AB + ABC
From Truth Table to Boolean Expression or Gate Diagram Given a truth table, you should be able to: 1. Write a Boolean expression for that truth table. Here’s how: a) For each row in the truth table with a 1 in the output column, list the corresponding AND term of the input variables. b) OR together all of the AND terms from Step a. 2. Draw a gate diagram that implements the truth table. Example: Write a Boolean expression and draw a gate diagram for the truth table on the next slide.
Example: From Truth Table to Boolean Expression or Gate Diagram ABCX 0000 0010 0101 0111 1000 1011 1100 1110