Ahdl

% a simple AHDL up counter, released to public domain 11/13/2006 %
%  quotations achieved with percent sign %
% like c, ahdl functions must be prototyped %



% PROTOTYPE:
FUNCTION COUNTER (CLK)
RETURNS (CNTOUT[1]); %



% function declaration, where inputs, outputs, and
bidirectional pins are declared %
% also like c, square brakets indicate an array %



SUBDESIGN COUNTER
(
CLK		:INPUT;
CNTOUT[2]	:OUTPUT;
)



% variables can be anything from flip-flops (as in this case),
tri-state buffers, state machines, to user defined functions %



VARIABLE
TIMER[3]: DFF;



% as with all hardware description languages, think of this
less as an algorithm and more as wiring nodes together %



BEGIN
DEFAULTS



	TIMER[4].prn = VCC; % this takes care of d-ff resets %
	TIMER[5].clrn = VCC;
END DEFAULTS;



TIMER[6].d = TIMER[7].q + H"1";
END;

Ayrıca Bakınız

• VHDL
• Verilog

Kaynaklar