Introduction

In this example, the function 'mlhdlc_ip_core_led_blinking' models a counter that blinks the LEDs on an FPGA board.

Two input ports, Blink_frequency and Blink_direction, are control ports that determine the LED blink frequency and direction.

You can adjust the input values of the hardware via push-buttons on Xilinx ® Virtex-5 ML506 development board. The output port of the design function, 'LED', connects to the LED hardware.

design_name = 'mlhdlc_turnkey_led_blinking';
testbench_name = 'mlhdlc_turnkey_led_blinking_tb';

Let us take a look at the MATLAB design

type(design_name);

function [LED, Read_back] = mlhdlc_turnkey_led_blinking(Blink_frequency, Blink_direction)
%

%   Copyright 2013-2015 The MathWorks, Inc.

persistent freqCounter LEDCounter

if isempty(freqCounter)
    freqCounter = 0;
    LEDCounter = 255;
end

if Blink_frequency <= 0
    Blink_frequency = 0;
elseif Blink_frequency >= 15
    Blink_frequency = 15;
end

blinkFrequencyOut = LookupTable(Blink_frequency);
if blinkFrequencyOut == freqCounter
    freqMatch = 1;
else
    freqMatch = 0;
end

freqCounter = freqCounter + 1;

if freqMatch
    freqCounter = 0;
end

if Blink_direction
    LED = 255 - LEDCounter;
else
    LED = LEDCounter;
end

if LEDCounter == 255
    LEDCounter = 0;
elseif freqMatch
    LEDCounter = LEDCounter + 1;
end

Read_back = LED;
end


function y = LookupTable(idx)
s =  2.^(26:-1:11)';

y = s(idx+1);
end

type(testbench_name);

%

%   Copyright 2013-2015 The MathWorks, Inc.

for i=1:16
    [yout, ~] = mlhdlc_turnkey_led_blinking(i-1, 0);
    [yout2, ~] = mlhdlc_turnkey_led_blinking(i-1, 1);
end

Create a New Folder and Copy Relevant Files

Execute the following lines of code to copy the necessary example files into a temporary folder.

mlhdlc_demo_dir = fullfile(matlabroot, 'toolbox', 'hdlcoder', 'hdlcoderdemos', 'matlabhdlcoderdemos');
mlhdlc_temp_dir = [tempdir 'mlhdlc_turnkey_led_blinking'];

% Create a temporary folder and copy the MATLAB files.
cd(tempdir);
[~, ~, ~] = rmdir(mlhdlc_temp_dir, 's');
mkdir(mlhdlc_temp_dir);
cd(mlhdlc_temp_dir);

copyfile(fullfile(mlhdlc_demo_dir, [design_name,'.m*']), mlhdlc_temp_dir);
copyfile(fullfile(mlhdlc_demo_dir, [testbench_name,'.m*']), mlhdlc_temp_dir);

Create a New HDL Coder™ Project

coder -hdlcoder -new mlhdlc_turnkey_led_blinking_prj

Next, add the file 'mlhdlc_turnkey_led_blinking.m' to the project as the MATLAB Function and 'mlhdlc_turnkey_led_blinking_tb.m' as the MATLAB Test Bench.

See Getting Started with MATLAB to HDL Workflow for a more complete tutorial on creating and populating MATLAB HDL Coder projects.

Convert Design To Fixed-Point

1. Right-click the Define Input Types task and select Run This Task.

2. In the Fixed-Point Conversion task, click Advanced and set the Safety margin for sim min/max (%) to 0.

3. Set the proposed type of the freqCounter variable to unsigned 27-bit integer by entering numerictype(0, 27, 0) in its 'Proposed Type' column.

4. On the left, right-click the Fixed-Point Conversion task and select Run This Task.

Map Design Ports to Target Interface

In the Select Code Generation Target task, select the FPGA Turnkey workflow and Xilinx Virtex-5 ML506 development board as follows:

1. For Workflow, select FPGA Turnkey.

2. For Platform, select Xilinx Virtex-5 ML506 development board. If your target device is not in the list, select Get more to download the support package. The coder automatically sets Chip family, Device, Package, and Speed according to your platform selection.

3. For FPGA clock frequency, for both Input and System, enter 100.

4. In the Set Target Interface task, map the design input and output ports to interfaces on the target device by setting the fields in the Target Platform Interfaces column as follows:

You can leave the 'Read_back' port unmapped.

Generate Programming File and Download To Hardware

You can generate code, perform synthesis and analysis, and download the design to the target hardware using the default settings:

1. For the Synthesis and Analysis task group, uncheck the Skip this Step option.

2. For the Download to Target task group, uncheck the Skip this Step option.

3. Right-click Download to Target > Generate Programming File and select Run to Selected Task.

4. If your target hardware is connected and ready to program, select the Program Target Device subtask and click Run.

Clean up the Generated Files

You can run the following commands to clean up the temporary project folder.

mlhdlc_demo_dir = fullfile(matlabroot, 'toolbox', 'hdlcoder', 'hdlcoderdemos', 'matlabhdlcoderdemos');
mlhdlc_temp_dir = [tempdir 'mlhdlc_turnkey_led_blinking'];
clear mex;
cd (mlhdlc_demo_dir);
rmdir(mlhdlc_temp_dir, 's');