Added StopWatch example for DOM and documentation testing.

1 files changed, 45 insertions, 0 deletions

diff --git a/testsuite/pyunit/dom/examples/StopWatch/Counter.vhdl b/testsuite/pyunit/dom/examples/StopWatch/Counter.vhdl
new file mode 100644
index 000000000..3ef284b98
--- /dev/null
+++ b/testsuite/pyunit/dom/examples/StopWatch/Counter.vhdl
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+-- Author:  Patrick Lehmann
+-- License: MIT
+--
+-- A generic counter module used in the StopWatch example.
+--
+library IEEE;
+use     IEEE.std_logic_1164.all;
+use     IEEE.numeric_std.all;
+
+use     work.Utilities.all;
+
+
+entity Counter is
+	generic (
+		MODULO : positive;
+		BITS   : natural := log2(MODULO)
+	);
+	port (
+		Clock      : in  std_logic;
+		Reset      : in  std_logic;
+		Enable     : in  std_logic;
+
+		Value      : out unsigned(BITS - 1 downto 0);
+		WrapAround : out std_logic
+	);
+end entity;
+
+
+architecture rtl of Counter is
+	signal CounterValue : unsigned(log2(MODULO) - 1 downto 0) := (others => '0');
+begin
+	process (Clock)
+	begin
+		if rising_edge(Clock) then
+			if ((Reset or WrapAround) = '1') then
+				CounterValue <= (others => '0');
+			elsif (Enable = '1') then
+				CounterValue <= CounterValue + 1;
+			end if;
+		end if;
+	end process;
+
+	Value      <= resize(CounterValue, BITS);
+	WrapAround <= Enable when (CounterValue = MODULO - 1) else '0';
+end architecture;