The EBAZ4205 board

The best resources I found to understand how to manage the board are:

• xjtuecho/EBAZ4205 
• https://theokelo.co.ke/getting-starting-with-ebaz4205-zynq-7000/

STEPS TO  CHECK IF THE BOARD IS OK

After 1 month my board arrived from China. 

As expected there's no 25MHz crystal for Ethernet but the board is hardware configured not to use it (a Zynq-7000 pin is connected to the 25MHz clock Ethernet chip input). 

The JTAG and UART connectors are present. 

1. Supply with +12V. It should work as expected in the section "first booting" of https://theokelo.co.ke/getting-starting-with-ebaz4205-zynq-7000/

2. See the wirings.

• 3 wires RXD TXD and GND (blue, green and yellow in the picture) to a PC serial port configured at 115200bps, 8 bit, stop bit, no parity 
• the 12V power supply directly soldered on the PCB (the 20 pin 2mm connectors will arrive from China at the end of August)  
• the Ethernet cable to the home router

 3. follow the instructions of xjtuecho/EBAZ4205 at paragraphs:

• "Reset the root password of built-in linux" and
• "Shut down the BTC miner program"

 4. Edit /etc/network/interfaces and uncomment only:

auto eth0 iface eth0 inet dhcp

 In this way you enable the ethernet port and a DHCP client on it to obtain an IP from your router (You do have a router with DHCP, don't you?)

5. Connect an ethernet cable to the ethernet port and then

reboot

6. I didn't want to buy an expensive JTAG programmer compatible with XILINK devices so I opted for this solution ft2232_to_digilent_jtag that transforms a FT2232 USB double UART into a double device:

• XILINX JTAG programmer
• UART

Now that you successfully checked your EBAZ420 board, you can go on!

PROGRAMMING THE EBAZ4205 WITH XILINX VIVADO

I found it more difficult than expected. VIVADO, VITIS IDE but especially PetaLinux are very powerful and complex instruments and their learning curve is very steep for me.

After many attempts,  I managed to get working this Vivado block design, using the HW SW IDE described in the next section. 

This block design configure the EBAZ4205 to create a clock generator (8-200 MHz) with a frequency programmable with a linux program. The HW logic, Linux and the programming software all run on the Zynq-7000 FPGA of the EBAZ4205. IMO this project lets me to setup and test all the different aspects (CPU/PS, PL, GPIO, Ethernet, Linux, boot from SD) for much more complex EBAZ4205 / Zynq-7000 projects. 

In this design please note that:

1. the PS groups the IPs (Intellectual Properties) building the Programmable System logic, i.e. the CPU, the reset block, the AXI block and the Ethernet block
2. the PS outputs the 25MHz FCLK_CLK3_0 to the pin U18 that in the EBAZ4205 is connected to the 25MHz Ethernet chip input. Without this clock the Ethernet port won't work!
3. the PS outputs the 50MHz FCLK_CLK0 going to:
   1. a 26 bits counter to divide the 25MHz clock and flash slowly (~0,5 seconds) the two red and green LEDs  
   2. a Clocking Wizard IP (clk_8M_66M) that outputs a programmable clock clk_66M (10 - 200 MHz) using a PLL
4. the clk_8M_66M frequency is programmed by AXI. See the connection between the PS M00_AXI and the clk_8M_66M s_axi_lite  

GLOSSARY