Added StopWatch example for DOM and documentation testing.

1 files changed, 90 insertions, 0 deletions

diff --git a/testsuite/pyunit/dom/examples/StopWatch/seg7_Display.vhdl b/testsuite/pyunit/dom/examples/StopWatch/seg7_Display.vhdl
new file mode 100644
index 000000000..c3771ba68
--- /dev/null
+++ b/testsuite/pyunit/dom/examples/StopWatch/seg7_Display.vhdl
@@ -0,0 +1,90 @@
+-- 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;
+use     work.StopWatch_pkg.all;
+
+
+entity seg7_Display is
+	generic (
+		CLOCK_PERIOD  : time := 10 ns;
+		REFRESH_RATE  : time := 200 us;
+		DIGITS        : positive
+	);
+	port (
+		Clock         : in  std_logic;
+
+		DigitValues   : in  T_BCD_Vector(DIGITS - 1 downto 0);
+		DotValues     : in  std_logic_vector(DIGITS - 1 downto 0) := (others => '0');
+
+		Seg7_Segments : out std_logic_vector(7 downto 0);
+		Seg7_Selects  : out std_logic_vector(DIGITS - 1 downto 0)
+	);
+end entity;
+
+
+architecture rtl of seg7_Display is
+	constant TIMEBASE_COUNTER_MAX : positive := REFRESH_RATE / (CLOCK_PERIOD * ite(IS_SIMULATION, 1_000, 1));
+
+	signal Timebase_Counter : unsigned(log2(TIMEBASE_COUNTER_MAX) - 1 downto 0) := (others => '0');
+	signal Timebase_Tick    : std_logic;
+
+	signal Digit_Select     : unsigned(log2(DIGITS) - 1 downto 0) := (others => '0');
+	signal Digit_Select_ov  : std_logic;
+
+	signal Digit            : T_BCD;
+	signal Dot              : std_logic;
+begin
+	-- refresh rate
+	process(Clock)
+	begin
+		if rising_edge(Clock) then
+			if (Timebase_Tick = '1') then
+				Timebase_Counter <= (others => '0');
+			else
+				Timebase_Counter <= Timebase_Counter + 1;
+			end if;
+		end if;
+	end process;
+
+	Timebase_Tick <= '1' when (Timebase_Counter = TIMEBASE_COUNTER_MAX - 1) else '0';
+
+
+	-- counter to select digits (time multiplexing)
+	process(Clock)
+	begin
+		if rising_edge(Clock) then
+			if (Timebase_Tick = '1') then
+				if (Digit_Select_ov = '1') then
+					Digit_Select <= (others => '0'); -- to_unsigned(5, Digit_Select'length);
+				else
+					Digit_Select <= Digit_Select + 1;
+				end if;
+			end if;
+		end if;
+	end process;
+
+	Digit_Select_ov <= '1' when (Digit_Select = DIGITS - 1) else '0';
+
+	-- multiplexer
+	Digit <= DigitValues(to_index(Digit_Select, DigitValues'high));
+	Dot   <= DotValues(to_index(Digit_Select, DotValues'high));
+
+	-- 7-segment encoder
+	enc: entity work.seg7_Encoder
+		port map (
+			BCDValue  => Digit,
+			Dot       => Dot,
+
+			Seg7Code  => Seg7_Segments
+		);
+
+
+	Seg7_Selects <= bin2onehot(Digit_Select, DIGITS);
+end architecture;