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Diffstat (limited to 'testsuite/vests/vhdl-ams/ashenden/compliant/digital-modeling/zmux.vhd')
-rw-r--r-- | testsuite/vests/vhdl-ams/ashenden/compliant/digital-modeling/zmux.vhd | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/testsuite/vests/vhdl-ams/ashenden/compliant/digital-modeling/zmux.vhd b/testsuite/vests/vhdl-ams/ashenden/compliant/digital-modeling/zmux.vhd new file mode 100644 index 000000000..2f27a8c96 --- /dev/null +++ b/testsuite/vests/vhdl-ams/ashenden/compliant/digital-modeling/zmux.vhd @@ -0,0 +1,88 @@ + +-- 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 + +entity zmux is +end entity zmux; + + +library util; use util.stimulus_generators.all; + +architecture test of zmux is + + signal sel0, sel1, d0, d1, d2, d3 : bit := '0'; + signal functional_z, equivalent_z : bit; + +begin + + functional_mux : block is + port ( z : out bit ); + port map ( z => functional_z ); + begin + + -- code from book + + zmux : z <= d0 when sel1 = '0' and sel0 = '0' else + d1 when sel1 = '0' and sel0 = '1' else + d2 when sel1 = '1' and sel0 = '0' else + d3 when sel1 = '1' and sel0 = '1'; + + -- end code from book + + end block functional_mux; + + -------------------------------------------------- + + equivalent_mux : block is + port ( z : out bit ); + port map ( z => equivalent_z ); + begin + + -- code from book + + zmux : process is + begin + if sel1 = '0' and sel0 = '0' then + z <= d0; + elsif sel1 = '0' and sel0 = '1' then + z <= d1; + elsif sel1 = '1' and sel0 = '0' then + z <= d2; + elsif sel1 = '1' and sel0 = '1' then + z <= d3; + end if; + wait on d0, d1, d2, d3, sel0, sel1; + end process zmux; + + -- end code from book + + end block equivalent_mux; + + -------------------------------------------------- + + stimulus : + all_possible_values( bv(0) => sel0, bv(1) => sel1, + bv(2) => d0, bv(3) => d1, + bv(4) => d2, bv(5) => d3, + delay_between_values => 10 ns ); + + verifier : + assert functional_z = equivalent_z + report "Functional and equivalent models give different results"; + +end architecture test; |