Subversion Repositories potato

-- The Potato Processor - A simple processor for FPGAs

-- (c) Kristian Klomsten Skordal 2014 - 2015 <kristian.skordal@wafflemail.net>

-- Report bugs and issues on <https://github.com/skordal/potato/issues>

library ieee;

use ieee.std_logic_1164.all;

entity tb_soc_uart is

end entity tb_soc_uart;

architecture testbench of tb_soc_uart is

        -- Clock signal:

        signal clk : std_logic := '0';

        constant clk_period : time := 10 ns;

        -- Reset signal:

        signal reset : std_logic := '1';

        -- UART ports:

        signal txd : std_logic;

        signal rxd : std_logic := '1';

        -- interrupt signals:

        signal irq_send_buffer_empty : std_logic;

        signal irq_data_received : std_logic;

        -- Wishbone ports:

        signal wb_adr_in  : std_logic_vector(1 downto 0) := (others => '0');

        signal wb_dat_in  : std_logic_vector(7 downto 0) := (others => '0');

        signal wb_dat_out : std_logic_vector(7 downto 0);

        signal wb_we_in   : std_logic := '0';

        signal wb_cyc_in  : std_logic := '0';

        signal wb_stb_in  : std_logic := '0';

        signal wb_ack_out : std_logic;

begin

        uut: entity work.pp_soc_uart

                port map(

                        clk => clk,

                        reset => reset,

                        txd => txd,

                        rxd => rxd,

                        irq_send_buffer_empty => irq_send_buffer_empty,

                        irq_data_received => irq_data_received,

                        wb_adr_in => wb_adr_in,

                        wb_dat_in => wb_dat_in,

                        wb_dat_out => wb_dat_out,

                        wb_we_in => wb_we_in,

                        wb_cyc_in => wb_cyc_in,

                        wb_stb_in => wb_stb_in,

                        wb_ack_out => wb_ack_out

                );

        -- Set up an internal loopback:

        rxd <= txd;

        clock: process

        begin

                clk <= '1';

                wait for clk_period / 2;

                clk <= '0';

                wait for clk_period / 2;

        end process clock;

        stimulus: process

        begin

                wait for clk_period * 2;

                reset <= '0';

                -- Write a 'P' (for Potato the Processor) to the UART:

                wb_adr_in <= b"00";

                wb_dat_in <= x"50";

                wb_we_in <= '1';

                wb_cyc_in <= '1';

                wb_stb_in <= '1';

                wait until wb_ack_out = '1';

                wait for clk_period;

                wb_stb_in <= '0';

                wait for clk_period;

                -- Write an 'o':

                wb_dat_in <= x"6f";

                wb_stb_in <= '1';

                wait until wb_ack_out = '1';

                wait for clk_period;

                wb_stb_in <= '0';

                wait for clk_period;

                wait;

        end process stimulus;

end architecture testbench;