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Diffstat (limited to 'testsuite/vests/vhdl-ams/ashenden/compliant/digital-modeling/mux.vhd')
-rw-r--r-- | testsuite/vests/vhdl-ams/ashenden/compliant/digital-modeling/mux.vhd | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/testsuite/vests/vhdl-ams/ashenden/compliant/digital-modeling/mux.vhd b/testsuite/vests/vhdl-ams/ashenden/compliant/digital-modeling/mux.vhd new file mode 100644 index 000000000..7baf3571d --- /dev/null +++ b/testsuite/vests/vhdl-ams/ashenden/compliant/digital-modeling/mux.vhd @@ -0,0 +1,68 @@ + +-- 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 mux is +end entity mux; + +architecture test of mux is + + constant prop_delay : time := 5 ns; + + signal a, b, sel, z : bit; + +begin + + -- code from book + + mux : process (a, b, sel) is + begin + case sel is + when '0' => + z <= a after prop_delay; + when '1' => + z <= b after prop_delay; + end case; + end process mux; + + -- end code from book + + + stimulus : process is + subtype stim_vector_type is bit_vector(0 to 3); + type stim_vector_array is array ( natural range <> ) of stim_vector_type; + constant stim_vector : stim_vector_array + := ( "0000", + "0010", + "0100", + "0111", + "1001", + "1010", + "1101", + "1111" ); + begin + for i in stim_vector'range loop + (a, b, sel) <= stim_vector(i)(0 to 2); + wait for 10 ns; + assert z = stim_vector(i)(3); + end loop; + wait; + end process stimulus; + + +end architecture test; |