Logic Synthesis From PLA Descriptions Using AutoLogicII

This section describes how you can use truth tables represented as a Programmable Logic Array files as inputs to AutoLogic II to produce simple combinational circuits.

1. Write a text file like the one for a full adder that follows.
   

   .i 3
   .o 2
   .ilb a b cin
   .ob cout s    #This is a comment
   .type f
   .phase 111
   000 00
   001 01
   010 01
   011 10
   100 01
   101 10
   110 10
   111 11
   .e
   

   In this file, .i 3 means there are three inputs, .o 2 means there are two outputs. The line .ilb a b cin names the inputs and ob cout s names the outputs. The line .type f is a default setting which makes any combination of inputs not listed in the offset (they're '0'). The .phase 111 makes the outputs all active high. The next eight lines are the inputs and outputs as listed in the .ilb and .ob lines. Don't cares are denoted with a - and the file ends with .e. Each line must have a carriage return at the end.

2. Make a directory eddm.
3. Start AutoLogic by typing alui.
4. After the AutoLogic II window opens, go to Setup in the pull down menu then Destination Technology and then xc4ke/default and OK.
5. In the pull down menu go to File, Open and Design.... The settings are:

   File Format: PLA
   Options:
   Library:work
   Cell:design_name
   View:pla
   Files:design_name.pla
   

   Where design_name is the name of your .pla file.

6. In the pull down menu, go to Optimize then Optimize.... Make the settings:

   Optimization Type: Area
   Area Optimization Options: Medium
   Factor
   

7. Lastly, go to File in the pull down menu then Save and EDDM.

   Model Name: (leave blank)
   GN Library Mapping: work eddm
   select Generate Schematic
   

PLA synthesis creates a symbol but the pins aren't sorted. Go to the section on Schematic Capture to see how to create a symbol to overwrite this one and add the ports and buffers to your design so that it can be downloaded to the Xilinx board. You will find the schematic sheet in the eddm directory.