Xilinx Vivado - Ebaz - blink LED in two ways.

• Project - PL blinking works, PS blinking hits bug
• Ebaz: blink an led using both PS and PL

The other thing now (not so new) is to do everything from within Vivado with little or no injection of files from behind the scenes. I may use vim to edit a file that I already have a vivado edit window looking at. This seems to work well as both vim and vivado let me know when the file has changed behind the scenes.

What we ended up with

 PDF of final design diagram

Start the project

I create a new project "ebaz_blink_3", skip introducing any sources during project creation, and take care to select the Ebaz board.

I use the + to add source files and add connect.v along with master.xdc as a constraint as follows:

module connect(
    input ps_red,
    output led
    );

    assign led = ! ps_red;

endmodule

set_property -dict { PACKAGE_PIN W14 IOSTANDARD LVCMOS33 } [get_ports { red_led }];
set_property -dict { PACKAGE_PIN W13 IOSTANDARD LVCMOS33 } [get_ports { green_led }];

I add an AXI gpio from IP, configure it as all outputs, 1 bit wide. I run connection automation, selecting all, but omitting GPIO.

Now I go to Sources, find "connect", right click and add it to the block diagram. I connect its input to the axi_gpio, make the output external and relabel it "red_led".

Now the FPGA setup is basically done. In the sources tab, under design sources, I select the design (design_1) right click to get a menu, select "create HDL wrapper", then "let vivado manage and auto update" and OK.

And I generate a bitstream. I click on the 2x2 matrix icon up top and it gets busy.

Finally, I use File -- Export -- Export Hardware. I take care to check "include bitstream". Exporting to local project is correct and I click OK.

On to the SDK

The story now is to replace the helloworld.c file. I expand sumatra and then src and double click on it to get an edit window. I right click, select rename, and call it "blinker.c".

Now I am going behind the scenes to actually edit content.

cd /home/tom/ebaz_blink_3/ebaz_blink_3.sdk/sumatra/src
vi blinker.c

Let's load things up and run them

[tom@trona ~]$ xvcd-pico
xvc-pico listening on port 2542

Now back to the SDK. Select "sumatra" from the hierarchy list on the left. Right click for menu. Run as -- Launch on hardware.

It works!

The red LED is blinking.

Make a change, add verilog to blink the green LED

Back to Vivado. Get rid of Hardware manager by clicking the "X" at the upper right.

I use add sources to add blinker.v. Double click on this to bring it up for edit. I copy and paste into the vivado edit window and make a few edits. This will take "clock" as input and yield "led" as output. I add this to the block diagram. I attach its input to FCLK_CLK0 (which is connected to many other things on the diagram). I make its output external and rename it "green_led".

I click the "generate bitstream" 2x2 matrix icon at the top of Vivado. It saves my project and asks nicely about regenerating, then away it goes. Finally we get a bitstream.

I launch hardware manager, then go to open target and notice a new entry in the next menu "recent targets". I select that and am back on the air without extra fuss.

It works!

The red LED is blinking at 1 Hz and the green light at 2 Hz.

And I see proper messages at 115200 baud over the serial port.

Here is the verilog for blinker.v that runs on the FPGA (PL):

module blinker (
    input clock,
    output led
    );

parameter p_CNT_xHZ = 12_500_000;

reg [99:0] r_CNT = 0;

reg  r_TOGGLE = 1'b0;

always @ (posedge clock)
    begin
      if (r_CNT == p_CNT_xHZ-1) // -1, since counter starts at 0
        begin
          r_TOGGLE <= ! r_TOGGLE;
          r_CNT    <= 0;
        end
      else
        r_CNT <= r_CNT + 1;
    end

    assign led = r_TOGGLE;

endmodule

#include 
#include "platform.h"
#include "xil_printf.h"
#include "xgpio.h"
#include "sleep.h"

int main()
{
    XGpio led_gpio;;
    int state = 0;

    init_platform();

    print("Here we go ....\n\r");

    XGpio_Initialize ( &led_gpio, XPAR_AXI_GPIO_0_DEVICE_ID);
    XGpio_SetDataDirection ( &led_gpio,1,0);

    for ( ;; ) {
	usleep ( 500000 );
	state = ! state;
	XGpio_DiscreteWrite ( &led_gpio, 1, state);
	print ( "beep\n\r" );
    }

    cleanup_platform();
    return 0;
}

// THE END