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authorTristan Gingold2013-12-20 04:48:54 +0100
committerTristan Gingold2013-12-20 04:48:54 +0100
commit6c3f709174e8e4d5411f851cedb7d84c38d3b04a (patch)
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Import vests testsuite
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+
+-- Copyright (C) 2002 Morgan Kaufmann Publishers, Inc
+
+-- This file is part of VESTs (Vhdl tESTs).
+
+-- VESTs is free software; you can redistribute it and/or modify it
+-- under the terms of the GNU General Public License as published by the
+-- Free Software Foundation; either version 2 of the License, or (at
+-- your option) any later version.
+
+-- VESTs is distributed in the hope that it will be useful, but WITHOUT
+-- ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+-- FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+-- for more details.
+
+-- You should have received a copy of the GNU General Public License
+-- along with VESTs; if not, write to the Free Software Foundation,
+-- Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+library ieee; use ieee.math_real.all;
+library ieee_proposed; use ieee_proposed.electrical_systems.all;
+
+entity lowpass is
+ generic ( fp : real := 10.0; -- pole in Hz for 'ztf
+ Fsmp : real := 10.0e3); -- sample frequency for 'ztf
+ port ( terminal input: electrical;
+ terminal output: electrical );
+end entity lowpass;
+
+----------------------------------------------------------------
+
+architecture ztf of lowpass is
+
+ quantity vin across input to electrical_ref;
+ quantity vout across iout through output to electrical_ref;
+ constant Tsmp : real := 1.0 / Fsmp; -- sample period
+ constant wp : real := fp * math_2_pi; -- pole in rad/s
+ constant n0 : real := Tsmp * wp; -- z0 numerator coefficient (a)
+ constant n1 : real := Tsmp * wp; -- z-1 numerator coefficient (b)
+ constant d0 : real := Tsmp * wp + 2.0; -- z0 denominator coefficient (c)
+ constant d1 : real := Tsmp * wp - 2.0; -- z-1 denominator coefficient (d)
+ constant num : real_vector := (n0, n1);
+ constant den : real_vector := (d0, d1);
+
+begin
+
+ vout == vin'ztf(num, den, Tsmp);
+
+end ztf;