1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62
|
-- 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_proposed; use ieee_proposed.electrical_systems.all;
entity sensor is
generic ( threshold : real; -- voltage threshold
tipd_clk : delay_length; -- input prop delay on clk
tipd_input : real; -- input prop delay on sensor input
topd_q : delay_length ); -- output prop delay on q
port ( terminal input : electrical; -- sensor analog input
signal clk : in bit; -- edgetriggered clock input
signal q : out bit ); -- sensor digital output
end entity sensor;
architecture detailed_timing of sensor is
quantity vin across input; -- analog input values
quantity v_delayed : voltage; -- input voltage delayed
signal clk_delayed : bit; -- clk input port delayed
signal q_int : bit; -- q output with zero delay
begin
input_port_delay : block is
begin
v_delayed == vin'delayed(tipd_input);
clk_delayed <= clk'delayed(tipd_clk);
end block input_port_delay;
AD_conversion : block is
begin
q_int <= '1' when vin'above(threshold) else
'0';
end block AD_conversion;
output_port_delay : block is
begin
q <= q_int'delayed(topd_q);
end block output_port_delay;
end architecture detailed_timing;
|