Specifications

132 Chapter 7—RAMs and Programmable Devices
Creating a PLA Device with Manual Data Entry
This section describes the steps necessary to create a PLA device and
directly enter the data that will be stored in it: Here is a summary of the for-
mat used to enter PLA data:
 Each PLA output is specified separately. The Wizard will step you
through the outputs one page at a time, starting with the least
significant output bit.
 Each line of text entered represents one product term (AND function).
Any number of product terms can be entered, including zero. If any
one of the product terms specified matches the input values, the output
will become active.
 Each product term line must consist of N characters, where N is the
number of device inputs. Whitespace characters are ignored and are not
included in this count. The first character on a line corresponds to the
most significant device input, the last character to the least significant.
 Each input character must be one of the following
 There is no comment mechanism.
 No error messages are given no matter what you put in the text!
To create the PLA device:
 Open the PROM/RAM/PLA Wizard by clicking on its button ( ) in
the toolbar.
 Select the PLA device type and click the Next button:
0 Active if corresponding input is low
1 Active if corresponding input is high
X or x Always active
LW Reference.bk Page 132 Monday, December 15, 2003 5:59 PM