Introduction: FPGA Cyclone IV DueProLogic - Push Button & LED
In this tutorial, we are going to use the FPGA to control external LED circuit. We are going to implement the following tasks
(A) Use the push buttons on FPGA Cyclone IV DuePrologic to control LED.
(B) Flash LED on & off periodically
Video demo
Lab menu: https://roywchpi.blogspot.com/2020/06/10-fpga-dueprologic-push-button-led.html
Step 1: Build Electronic Circuit
Step 2: Check the Pin Planner and Edit Verilog Code
Step 3: Edit Verilog Code
When you buy FPGA DueProLogic, you should receive a DVD. After you open "Projects_HDL", you should see the original code file
Add the highlighted code. It registers the I/O ports and assign numbers to the ports.
output wire [7:0] XIO_1, //XIO -- D2-D9
output wire [5:0] XIO_2, //XIO -- D10-D12
output wire [5:0] XIO_3, //XIO -- D22-D29
input wire [5:0] XIO_4, //XIO -- D30-D37
input wire [5:0] XIO_5, //XIO -- D38-D45
output wire [4:0] XIO_6_OUT, //XIO -- D46-D53
input wire [31:5] XIO_6, //XIO -- D46-D53
output wire [2:0] XIO_7, //XIO -- D69,D70,D71,D74,D75,D76
input wire UBA, //Push Button Switches
input wire UBB //Push Button Switches
assign XIO_1[3] = start_stop_cntrl;
assign XIO_2[1] = start_blinky; //LED flash LED on and off
assign XIO_2[2] = 1'b1; //output HIGH
assign XIO_2[3] = ~UBA; //Push button A
assign XIO_2[4] = UBB; //Push button B
assign c_enable = XIO_5[2];
assign LEDExt = XIO_5[5];
Then we have to set a delay timer. Comment the original timer code and write a new timer function
//-----------------------------------------------
// LED Blinky start
//-----------------------------------------------
/*
always @(posedge CLK_66 or negedge RST)
begin
if(!RST)
start_blinky <= 1'b0;
else
begin
if(control_register[7:4] > 0)
start_blinky <= 1'b1;
else
start_blinky <= 1'b0;
end
end
*/
reg [31:0] ex;
initial begin
ex <= 32'b0;
start_blinky <= 1'b0;
end
always @(posedge CLK_66)
begin
ex <= ex + 1'b1;
if(ex > 100000000) //flash on/off ~1.6 seconds , clock 66MHz
begin
start_blinky <= !start_blinky;
ex <= 32'b0;
end
end
//-----------------------------------------------
// LED Delay Timer Counter
//-----------------------------------------------
/*
always @(posedge CLK_66 or negedge RST)
begin
if(!RST)
led_delay_counter <= TIMER_LOW_LIMIT;
else
begin
if(state[SELECT_MODE])
led_delay_counter <= timer_value;
else if(state[WAIT_FOR_TIMER])
led_delay_counter <= led_delay_counter - 1'd1;
end
end
*/
Step 4: Compile Verilog Code
Press "Start Compilation" in Quartus, no error message should be generated.
If you receive error message about multiple pins. Go to Assignments -> Device -> Device and Pin Options -> Dual-Purpose Pins -> change the value of the appropriate pin to "Use as regular I/O".
After compilation, you should get pof output file directly. If your software is not up-to-date, you may get sof file only. When it happens, click "File" in Quartus -> "convert programming files". Change the settings which are marked by red boxes.
Step 5: Let's Try It
After all, it should work!!! The yellow LED is always on. The red LED is flashing. The blue LED is turned off if you press button B. The green LED is turned on if you press button A
