Cadence Mixed-Signal Circuit Design Environment User Guide
The Mixed-Signal Interface
October 2003
21
Product Version 5.0
interface net, a warning is generated. A nonsupply global net is either a design error or you
must provide the appropriate analog or digital stimulus for the net.
Classes of IE Models
An interface element (IE) macro model class is based on the direction and data type of the
signal from one simulator to another.
An IE macro model is based on specifications from the digital component. The direction of
the signal flow is determined by the direction of the terminal of the digital instance connected
to the interface net. The direction is either from a circuit simulator to a logic simulator or from
a logic simulator to a circuit simulator.
The data type that is communicated is either analog or digital. The data type of the interface
element is determined by the
ieDataType
property of the terminal in the symbol cellview.
The A2D and D2A interface elements use digital data types. They communicate the logic
value and time of transition of digital events. The digital values communicated are 0, 1, X, or
Z. The D2A interface element transforms a digital event into the voltage, transition time, and
impedance of a source. The A2D interface element transforms the voltage of a net into a
digital event.
Class
Direction
Data Type
A2D
(analog to digital)
From the circuit simulator to the logic
simulator
Digital
D2A
(digital to analog)
From the logic simulator to the circuit
simulator
Digital
A2AO
(analog to analog out)
From the circuit simulator to the logic
simulator
Analog
A2AI
(analog to
analog in)
From the logic simulator to the circuit
simulator
Analog
Class
Direction
Data Type
A2D
(analog to digital)
From the circuit simulator to the logic
simulator
Digital
D2A
(digital to analog)
From the logic simulator to the circuit
simulator
Digital