Specifications

100 Chapter 6—Primitive Devices
Pin Inversion
In addition to the pin function options described in this chapter, any pin on
any device can be inverted by specifying a value in the Invert.Pin attribute
field. Any non–empty value will cause the pin logic to be inverted.
 See Chapter 7, Simulation, for more information
Gates and Buffers
The primgate.clf library contains the primitive gates that have a built–in
simulation function. The NOT, AND, NAND, OR, NOR, XOR, and
XNOR devices behave according to the appropriate truth tables for such
devices. Any gate input which is in the Don’t Know, High Impedance, or
Conflict state is treated as a Don’t Know. A gate with a Don’t Know input
will not necessarily produce a Don’t Know output. For example, if one
input of an AND gate is low, the output will be low, regardless of the state
of the other input—as in the following truth table:
A B OUT
00 0
0 1 0
0 X 0
100
111
1XX
X00
X1X
XXX
LW Reference.bk Page 100 Monday, December 15, 2003 5:59 PM