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VHDL-AMS is a derivative of the hardware description language VHDL (IEEE standard 1076-1993). It includes analog and mixed-signal extensions (AMS) in order to define the behavior of analog and mixed-signal systems (IEEE 1076.1-1999).

The VHDL-AMS standard was created with the intent of enabling designers of analog and mixed signal systems and integrated circuits to create and use modules that encapsulate high-level behavioral descriptions as well as structural descriptions of systems and components.[1]

VHDL-AMS is an industry standard modeling language for mixed signal circuits, it provides both continuous-time and event-driven modeling semantics, and so is suitable for analog, digital, and mixed analog/digital circuits. It is particularly well suited for verification of very complex analog, mixed-signal and radio frequency integrated circuits.

Code example[edit]

In VHDL-AMS, a design consists at a minimum of an entity which describes the interface and an architecture which contains the actual implementation; in addition, most designs import library modules. Some designs also contain multiple architectures and configurations.

A simple ideal diode in VHDL-AMS would look something like this:

-- (this is a VHDL comment)

library IEEE;
use IEEE.math_real.all;
use IEEE.electrical_systems.all;

-- this is the entity
entity DIODE is
   generic (iss : current := 1.0e-14;  -- Saturation current
            af  : real    := 1.0;      -- Flicker noise coefficient
            kf  : real    := 0.0);     -- Flicker noise exponent
   port (terminal anode, cathode : electrical);      
end entity DIODE;

architecture IDEAL of DIODE is
  quantity v across i through anode to cathode;
  constant vt : voltage := 0.0258;     -- Thermal voltage at 300 K

  i == iss * (exp(v/vt) - 1.0);

end architecture IDEAL;

VHDL-AMS Simulators[edit]


  1. ^ Christen E., Bakalar K.,"VHDL-AMS-a hardware description language for analog and mixed-signal applications",Circuits and Systems II: Analog and Digital Signal Processing, IEEE Transactions on [see also Circuits and Systems II: Express Briefs, IEEE Transactions on] Volume 46, Issue 10, Oct. 1999, pp. 1263 - 1272.

See also[edit]