HDMI Test pattern generated by the FPGA displayed on an external LCD TV
Zedboard Switches with OLED Display
  1. Format an SD card with one vfat partition (this is the default for the SD card that comes with the Zedboard)
  2. Download http://vserver.13thfloor.at/Stuff/AXIOM/ALPHA/axiom_alpha_hdmi_test_v0.1.zip and put all the files in the zipped folder onto your SD card (not into a subfolder)
  3. Connect a monitor to the Zedboards HDMI port and turn on the monitor.
  4. Shift all switches on the Zedboard down
  5. Boot the Zedboard
  6. After booting is complete turn switch SW3 (fifth from the left) up
  7. Play around with the switches to alter the generated patterns

1 Notes

If the Zedboard is booting via TFTP by default use an UART / serial console and interrupt the bootloader then type:

env default -f

The last command will reboot the Zedboard - alternatively you can also push the right pink pushbutton on the Zedboard.

2 Commands

The lower 4 switches select the pattern, while the upper four modify the size: black, red, green, blue, lines h/v/both, bars h/v and checkers

The idea is to check this on different displays and if necessary adjust the timing parameters

There is, for example, a configuration for 1280x768 as well which can be activated by running:


The default 1080p mode:


If you unplug and replug a display, you need to execute:


You can adjust the pixel clock with:

echo 135000000 >/sys/class/fclk/FPGA2/set_rate

In 1280 mode for example you need to adjust the pixel clock to:

echo 75000000 >/sys/class/fclk/FPGA2/set_rate

The selected rate can be read back by typing:

cat /sys/class/fclk/FPGA2/set_rate

2.1 Registers

devmem 0x60000000 32 1664       # total width
devmem 0x60000004 32 798        # total height
devmem 0x60000008 32 1280       # display width
devmem 0x6000000c 32 768        # display height
devmem 0x60000010 32 15         # front porch
devmem 0x60000014 32 2          # vertical blank
devmem 0x60000018 32 1344       # h-sync start
devmem 0x6000001c 32 1472       # h-sync end
devmem 0x60000020 32 771        # v-sync start
devmem 0x60000024 32 778        # v-sync end   
devmem 0x60000028 32 41         # pattern size