Lab 3 & 4 Discussion EE414/514 VHDL Design September 25

Lab 3 Hint - Package and Library Library IEEE; use ieee.std_logic_arith.all; use ieee.std_logic_unsigned.all; USE IEEE.Std_LOGIC_1164.all; entity adder is port ( a_in : in std_logic_vector (3 downto 0); b_in : in std_logic_vector (3 downto 0); c_out : out std_logic_vector (3 downto 0)); end adder; architecture adder_arch of adder is begin process (a_in, b_in) variable carry : std_logic_vector (4 downto 0); variable sum :std_logic_vector (3 downto 0); begin carry (0) := '0'; for i in 0 to 3 loop sum (i) := a_in(i) xor b_in(i) xor carry(i); carry (i+1) := (a_in(i) and b_in(i)) or (b_in(i) and carry (i)) or (carry (i) and a_in(i)); end loop; c_out <= sum; end process; end adder_arch; What these two means?

Lab 3 Package and Library Go to library IEEE, You will find: PACKAGE std_logic_1164 IS … FUNCTION "and" ( l : std_ulogic; r : std_ulogic ) RETURN UX01; … END std_logic_1164;

Include User’s Design Lib In Lab 3 -Make your library visible to design Put two design in the same workspace – First design a single byte counter – At the same workspace, design a two-byte counter Library – First create a library with your design-single byte counter – Attach your library to two-byte counter

Include User’s Design Lib In Lab 3 -- Package

Include User’s Design Lib In Lab 3 -- Use Package

Connection of Prototype Boards in Lab 4 JTAG 7-S LED LED XC95108 JTAG CLOCK Reset XC2S200 -PQ208 LCD Keypad Switch Expansion Board Dio2 System Board Digilab2 CONNECTORCONNECTOR

Features of Prototype Board - System Board Digilab 2 Spartan2 XC2S200-PQ208 – Select correct devices in Xilinx ISE – Pin location 50 MHZ CLOCK – Speed of your design – Source of the clock divider Configuration mode: JTAG – Select JTAG clock as startup clock Expansion Connector

Block Diagram of Prototype Board - System Board Digilab 2

Function Implemented On System Board - Timer Timer and Clock Divider Module process (CLK, MR) begin if MR = '0' then L1: for count_value in 18 downto 0 loop QOUT(count_value) <= '0'; end loop L1; else if (CLK'event and CLK='1') then QOUT <= QOUT + 1; end if; end process; SWCLK <= QOUT(18); -- using appropriate taps off the counter as divided SMCLK <= QOUT(12); -- clock outputs How to Calculate the factor of Divider ?

Function Implemented On System Board - Example of State Machine State Machine, State Reset, Start_T, … are defined COMB_PROC: process (CLK, MR) -- This is the combinational part begin if (MR = '0') then NS <= RESET; elsif (CLK'event and CLK = '1') then case NS is -- case # appears in () to aid in coding when RESET => -- (1) if S = '0' then NS <= START_T; -- go to this state when the S button is pressed; else NS <= RESET; -- otherwise stay in this same state. end if; when START_T => -- (2)transitional states have the outputs of the corresponding stable state. if S = '1' then NS <= START; else NS <= START_T; end if;

Features of Prototype Board - Expansion Board Dio2 XC95108 CPLD Display Units – 16*2 character LCD – 4 seven-segment LED display – 16 LED of various colors Input Devices – 15-button keypad – 8 slide switches

Block Diagram of Prototype Board - Expansion Board Dio2 Bus for exchange data between Dio2 and Digilab2 boards

How to Access The Interface Units - LCD Signals – D7-D0 Data Bus – LCD_R/W – LCD_RS – LCD_E

How to Access The Interface Units - LCD Code constant LCD_CMDS : LCD_CMDS_T := ( 0 => "00"&X"01", -- Clear The Display 1 => "00"&X"38", -- Set interface data width,2 line,5*8 dots 2 => "00"&X"0c", -- Set display on, cursor off and blink off 3 => "00"&X"02", -- Return Cursor to Home 4 => "10"&X"4f", -- write the display data “Ohio …” 5 => "10"&X"68", 6 => "10"&X"69", 7 => "10"&X"6f",

How to Access The Interface Units -Keypad, Switches, LED, 7-S LED Display All these devices are mapped to corresponding address Read the data from certain address to obtain the status of the input devices, such as keypad and switches Write the data to certain address to turn on/off LED and modify the display data on 7-S LED display

How to Access The Interface Units -Keypad, Switches, LED, 7-S LED Display Code signal btns : std_logic_vector(14 downto 0); push buttons are mapped to bits of the vector signal firstTwoNum,LastTwoNum: std_logic_vector(7 downto 0); -- There are four 7-s LED display units, the first two are mapped to vectorFirstTwoNum -- Another two are mapped to vector LastTwoNum RSTIN=>btns(10), -- Reset input is mapped to “A” button RUNIN=>not btns(11), -- Run input is mapped to “A” button Q3 => FirstTwoNum(3 downto 0), -- Q3 is displayed on 7-S LED Q2 => FirstTwoNum(7 downto 4), -- Q2 is displayed on 7-S LED Q1 => LastTwoNum(3 downto 0), -- Q1 is displayed on 7-S LED Q0 => LastTwoNum(7 downto 4), -- Q0 is displayed on 7-S LED