January 2, 2021

EBAZ4205 Bitcoin miner board -- Overview

My first one of these set me back $17.28 back in January of 2021. The price shown was $11.70 but shipping took it to $17.28

I just ordered 4 more of them (in December of 2022, some 2 years later). The price for the four of them was $120 including shipping charges, so they now cost $30 each. They won't be available forever given that these are boards evicted from an obsolete bitcoin mining rig. This most recent purchase had the boards "all fixed up" with the serial and jtag headers as well as the SD card socket soldered on for me. Nicely enough, these also have the crystal soldered on for the ethernet.

What have I got?

Here are some notes thrown together shortly after my first board arrived.

My board is labeled EBAZ4205 and is about 4 inches square. It came with a little ziplock bag containing "accessories", which was a nice touch. The bag contained a 4 pin header for the serial console, and a barrel connector for power, both of which I used. It also contains a 14 pin header for JTAG, and SD card socket, and a mysterious blue single jumper wire.

Apparently this was the "control" board for a bunch of bitcoin miner ASIC boards (not included, and probably of little interest). The whole package was called the "Ebit E9+ BTC miner"

The star of the show is a Xilinx ZYNQ chip, namely an XC7Z010.

The Xilinx chip is an SoC with a dual core ARM and an FPGA. The literature calls the ARM section the "PS" (processing system) and the FPGA section the "PL" (programmable logic). The XC7Z010 is an "Artix-7" FPGA (with 28K logic elements).

Just the chip on Digikey sells for about $65. An evaluation board for the chip sells for about $200.

The two ARM processors on my particular board run at 667 Mhz.

The board adds 256M of DDR3 memory along with 128M of flash.

It has a 14 pin header (and they gave me the header to solder in), which is a JTAG connector. There is a 100M ethernet port (an RJ-45). There is a UART Port (4 pins near the RJ-45 and LEDs).

There are three big chips other than the ZYNQ:

The IP101GA is an ethernet transceiver, and a 65 page datasheet is available. Mine seems to be missing the 25 Mhz crystal near the ethernet, along with the capacitors that should go with it. This is odd given that the other components for ethernet are present. I wonder if there is some other way for it to get the clock. There must be, because the network works just fine without the crystal.
( -- And indeed there is, the clock can be supplied by the FPGA itself, but this requires a bitstream configured to do such to be loaded into the FPGA. Apparently this is done by U-Boot, but if you load a bitstream of your own, you will need to take this into account.)

References

The Github page by xjtuecho has a very nice guide to getting started with this thing.

The Hackaday article mentions something called "Vivado" to work with the FPGA.

Antminer

There is another board (the S9 Antminer) also on sale on AliExpress, but for $59, which is more than I want to spend to fool around. Some searching shows others for $20 and a variety of models. It has the same XC7Z010 chip, but provides a gigabit ethernet transciever and more memory (as much as 1G). I don't feel that these provide any overwhelming advantage for anything I want to do, so I am ignoring them for now.

Feedback? Questions? Drop me a line!

Tom's Computer Info / tom@mmto.org