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[/] [onewire/] [trunk/] [HDL/] [ds1820_mstr_tb.vhd] - Rev 3
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---------------------------------------------------------------------------------- -- <c>2018 william b hunter -- This file is part of ow2rtd. -- -- ow2rtd is free software: you can redistribute it and/or modify -- it under the terms of the GNU Lessor General Public License as published by -- the Free Software Foundation, either version 3 of the License, or -- (at your option) any later version. -- -- ow2rtd 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 Lessor General Public License -- along with ow2rtd. If not, see <https://www.gnu.org/licenses/>. ----------------------------------------------------------------------------------- -- Create Date: 5/15/2018 -- file: ds1820_mstr_tb.vhd -- description: Testbench for both the ow_mstr and ds1820_mster modules -- ------------------------------------------------------------------------------------- library IEEE; use IEEE.STD_LOGIC_1164.ALL; use IEEE.numeric_std.all; use ieee.std_logic_textio.all; library std; use STD.textio.all; ------------------------------------------------------------------------------------- -- Entity declaration ------------------------------------------------------------------------------------- entity ds1820_mstr_tb is end ds1820_mstr_tb; ------------------------------------------------------------------------------------- -- Architecture declaration ------------------------------------------------------------------------------------- architecture sim of ds1820_mstr_tb is ------------------------------------- -- Check Temps Proceedure --- ------------------------------------- --check_temp - proceedure to check the output data, temp and tempidx, against expected values procedure check_temp ( signal temp : in signed(15 downto 0); --the temp reported from the DUT signal idx : in unsigned(4 downto 0); --the index of the sensor (sensor number) from the DUT exptemp : in signed(15 downto 0); --expected temperature value expidx : in unsigned(4 downto 0)) --expected index value is variable myline : line; variable dec : integer; variable frac : integer; begin --line := ""; if idx /= expidx then write(myline,string'("Error: wrong idx, expected ")); write(myline,to_integer(expidx)); write(myline,string'(", got ")); write(myline,to_integer(idx)); writeline(output,myline); assert false report "bad tempidx value" severity error; end if; if temp /= exptemp then --write(output, std_logic_vector(temp)); write(myline,string'("Error: wrong temp on sensor ")); write(myline,to_integer(expidx)); write(myline,string'(", expected ")); dec := to_integer(exptemp) / 16; frac := ((to_integer(exptemp) - 16*dec)*100)/16; write(myline,dec); write(myline,string'(".")); write(myline,frac); write(myline,string'(", got ")); dec := to_integer(temp) / 16; frac := ((to_integer(temp) - 16*dec)*100)/16; write(myline,dec); write(myline,string'(".")); write(myline,frac); write(myline,string'(", got ")); writeline(output,myline); assert false report "bad temp value" severity error; end if; end procedure check_temp; ------------------------------------------- --- Signal declaration --- ------------------------------------------- constant clkfreqmhz : integer := 100; --clock frequency in mhz constant halfperiodns : time := 1000 ns /(clkfreqmhz*2);--half the clock period signal clk : std_logic; constant CONVERSION_TIME : integer := 188; --ADC conversion time in ms signal srst : std_logic := '0'; --synchronous reset signal rst_cntr : unsigned(7 downto 0):= x"ff"; signal stb1us_cntr : integer range 1 to clkfreqmhz := 1; --counter used to generate stb1us signal stb1us : std_logic := '0'; --strobe 1 us, goes high for one clock every 1 us signal search_init : std_logic := '0'; --triggers the search module signal temp_init : std_logic := '0'; --triggers the initialization module signal temp_conv : std_logic := '0'; --triggers the temperature conversion signal temp_read : std_logic := '0'; --triggers the reading of the temperature results signal ow_busy : std_logic; -- the one wire bus is busy signal ow_err : std_logic; --there is an error on the one wire bus signal temp : signed(15 downto 0); --signed temp from sensor, value is 16 times the temp in C signal tempidx : unsigned(4 downto 0); --index of the current temp sensor signal tempstb : std_logic; --strobe to indicate an updated temp sensor value signal owin : std_logic; --one wire input to dut signal owout : std_logic; --one wire output from dut signal dio : std_logic; --one wire bus begin ------------------------------------- -- global timing signals --- ------------------------------------- p_osc : process begin clk <= '0'; wait for halfperiodns; clk <= '1'; wait for halfperiodns; end process p_osc; p_rst : process begin srst <= '1'; wait for 5 us; wait until clk = '1'; srst <= '0'; wait; end process p_rst; --generate a 1 us strobe for timing p_stb1us : process(clk) begin if rising_edge(clk) then if srst = '1' then stb1us <= '0'; stb1us_cntr <= 1; else if stb1us_cntr = clkfreqmhz then stb1us <= '1'; stb1us_cntr <= 1; else stb1us <= '0'; stb1us_cntr <= stb1us_cntr + 1; end if; end if; end if; end process p_stb1us; ------------------------------------- -- DUT --- ------------------------------------- --ow_mstr - DUT (device under test) -- one wire master - this performs all the one wire logic -- such as configuring and reading the DS1820 devices u_dut : entity work.ds1820_mstr(rtl) port map( --global signals clk => clk, srst => srst, stb1us => stb1us, --1 us strobe busy => ow_busy, err => ow_err, --high level interfaces, lets this module do the heavy lifting. For microprocessor control, search_stb => search_init, --searches for devices on bus temp_init => temp_init, --initiates temperature read from all devices temp_conv => temp_conv, --initiates temperature read from all devices temp_read => temp_read, --initiates temperature read from all devices temp => temp, --temperatures read from temp devices tempidx => tempidx, --temperatures index tempstb => tempstb, --temperatures ready strobe --one wire bus interface, requires external 5k resistor on bus owin => owin, --one wire input owout => owout --one wire output ); ----------------------------------------- -- one wire bus, open collector --- ----------------------------------------- --handle in/out nature of one wire interface dio <= '0' when owout = '0' else 'Z'; --output, only drives low, tristates when not low, external 5k pullup owin <= '0' when dio = '0' else '1'; --input, make sure H,Z,1 all map to '1' for simulation dio <= 'H'; --simulates the external pullup resistor ----------------------------------------- -- test bench control and checks --- ----------------------------------------- --p_control - controls the testing, initiates commands to the DUT p_control : process begin search_init <= '0'; --searches for devices on bus temp_init <= '0'; --initiates temperature read from all devices temp_conv <= '0'; --initiates temperature read from all devices temp_read <= '0'; --initiates temperature read from all devices --wait for reset and a bit of time to settle wait for 10 us; --initiate a search of the one wire devices on the bus wait until clk = '0'; search_init <= '1'; wait until clk = '0'; search_init <= '0'; wait until clk = '0'; --wait for search to complete wait until ow_busy = '0'; wait until clk = '0'; --initialize all the temperature sensors on the bus wait until clk = '0'; temp_init <= '1'; wait until clk = '0'; temp_init <= '0'; wait until clk = '0'; --wait for search to complete wait until ow_busy = '0'; wait for 5 us; --start conversions on all the sensors wait until clk = '0'; temp_conv <= '1'; wait until clk = '0'; temp_conv <= '0'; wait until clk = '0'; --wait for conversion commands to complete wait until ow_busy = '0'; --now wait until the conversions are actually complete wait for 190 ms; --read the temp from all the sensors wait until clk = '0'; temp_read <= '1'; wait until clk = '0'; temp_read <= '0'; wait until clk = '0'; --wait for all reads to take place wait until ow_busy = '0'; wait until clk = '0'; --now wait until the conversions are actually complete wait; end process p_control; --p_check - checks the output of the DUT and alerts if it is incorrect p_check : process variable exptemp : signed(15 downto 0); variable expidx : unsigned(4 downto 0); begin --check data from sensor 1 wait until tempstb = '1'; exptemp := to_signed(-24,16); -- -1.5C expidx := to_unsigned(0,5); check_temp(temp,tempidx,exptemp,expidx); --check data from sensor 2 wait until tempstb = '1'; exptemp := to_signed(1844,16); -- +115.25C expidx := to_unsigned(1,5); check_temp(temp,tempidx,exptemp,expidx); --check data from sensor 2 wait until tempstb = '1'; exptemp := to_signed(916,16); -- +57.25C expidx := to_unsigned(2,5); check_temp(temp,tempidx,exptemp,expidx); wait for 5 us; assert false report "Test completed" severity note; wait; end process; p_error : process begin wait until ow_err = '1'; assert true report "Bus error reported" severity error; end process; -------------------------------------------- -- Simulated OW bus devices, ds1820 --- -------------------------------------------- --simulated temperature sensor u_ds18b20_1 : entity work.ds18b20_sim(sim) generic map ( timing => "min", devid => x"00a0458d3ea2be28" ) port map ( --dio => dio1, pwrin => '1', dio => dio, tempin => -1.54 ); --simulated temperature sensor u_ds18b20_2 : entity work.ds18b20_sim(sim) generic map ( timing => "min", devid => x"002984456a32bf28" ) port map ( --dio => dio2, pwrin => '1', dio => dio, tempin => 115.3 ); --simulated temperature sensor u_ds18b20_3 : entity work.ds18b20_sim(sim) generic map ( timing => "min", devid => x"0083726dab32bf28" ) port map ( --dio => dio3, pwrin => '1', dio => dio, tempin => 57.25 ); end sim;
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