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Diffstat (limited to 'testsuite/vests/vhdl-93/ashenden/compliant/ch_05_fg_05_19.vhd')
-rw-r--r-- | testsuite/vests/vhdl-93/ashenden/compliant/ch_05_fg_05_19.vhd | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/testsuite/vests/vhdl-93/ashenden/compliant/ch_05_fg_05_19.vhd b/testsuite/vests/vhdl-93/ashenden/compliant/ch_05_fg_05_19.vhd new file mode 100644 index 000000000..99e4c16bb --- /dev/null +++ b/testsuite/vests/vhdl-93/ashenden/compliant/ch_05_fg_05_19.vhd @@ -0,0 +1,115 @@ + +-- Copyright (C) 1996 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 + +-- --------------------------------------------------------------------- +-- +-- $Id: ch_05_fg_05_19.vhd,v 1.2 2001-10-26 16:29:34 paw Exp $ +-- $Revision: 1.2 $ +-- +-- --------------------------------------------------------------------- + +entity fg_05_19 is +end entity fg_05_19; + + +architecture test of fg_05_19 is + + constant scheduling_delay : delay_length := 5 ns; + + subtype request_type is natural range 0 to 20; + type server_status_type is (ready, busy); + + signal first_priority_request, + first_normal_request, + reset_request : request_type := 0; + signal functional_request, equivalent_request : request_type; + signal priority_waiting : boolean := false; + signal server_status : server_status_type := busy; + +begin + + functional_scheduler : block is + port ( request : out request_type ); + port map ( request => functional_request ); + begin + + -- code from book + + scheduler : + request <= first_priority_request after scheduling_delay + when priority_waiting and server_status = ready else + first_normal_request after scheduling_delay + when not priority_waiting and server_status = ready else + unaffected + when server_status = busy else + reset_request after scheduling_delay; + + -- end code from book + + end block functional_scheduler; + + -------------------------------------------------- + + equivalent_scheduler : block is + port ( request : out request_type ); + port map ( request => equivalent_request ); + begin + + -- code from book + + scheduler : process is + begin + if priority_waiting and server_status = ready then + request <= first_priority_request after scheduling_delay; + elsif not priority_waiting and server_status = ready then + request <= first_normal_request after scheduling_delay; + elsif server_status = busy then + null; + else + request <= reset_request after scheduling_delay; + end if; + wait on first_priority_request, priority_waiting, server_status, + first_normal_request, reset_request; + end process scheduler; + + -- end code from book + + end block equivalent_scheduler; + + -------------------------------------------------- + + stimulus : process is + begin + first_priority_request <= 10; wait for 20 ns; + first_normal_request <= 5; wait for 20 ns; + server_status <= ready; wait for 20 ns; + server_status <= busy; wait for 20 ns; + priority_waiting <= true; wait for 20 ns; + server_status <= ready; wait for 20 ns; + first_normal_request <= 7; wait for 20 ns; + first_priority_request <= 12; wait for 20 ns; + + wait; + end process stimulus; + + verifier : + assert functional_request = equivalent_request + report "Functional and equivalent models give different results"; + +end architecture test; |