SqueakyBoard

A self-designed ZYNQ 7010 FPGA development board

Main Features

• 4-layer, 9.9 cm x 9.9 cm, meets JLCPCB requirements, friendly for hand-soldering, cost-optimized
• 28 K logic elements & Vivado and Xilinx SDK compatible, using the programmable logic of ZYNQ 7010 CLG400

Connectivity

• Pluggable CJMCU-FT232HL as JTAG downloader or USB-UART bridge
• Reserved standard 2x7 JTAG port
• SPI PSRAM up to 64 MBytes
• Basic HDMI
• USB-to-UART
• Two USB ports, one connected directly and one via CH375b
• Micro SD Card
• Pluggable W5500-Lite module
• Up to 4 PMOD connector
• 4 LEDs, 2 slide switches, 2 push buttons
• Configuration via PS-side QSPI flash
• Power input via JTAG downloader, USB-to-UART, or 5V jack

Testing

Untested parts:

• 5V jack input
• SD card only SPI is tested
• PSRAM only the first(U4), up to QPI mode 62.5MHz -- this is because laziness
• USB direct connect only PS2 keyboard tested
• Use 7020 instead of 7010 -- is power supply sufficient?

Parts need remedy:

• Slide switch need VCC connection removed to avoid short -- it's more bad switch than bad design
• USB(direct connection) needs pullup constraint because logic level problem(FPGA 3.3V vs PS2 5V), but it do work for some (extremely cheap) keyboards
• The crystal on front side connected to a pin with warning, so is not used

Failed parts:

• USB to UART -- D- and D+ on the chip was accidentally inverted

Design Files

Sorry but I use Altium Designer. altium/ contains design files, altium_pdf/ contains readable schematic(with comment of failed parts) and layout.

src/ contains example project source, bitstream, pre-generated SPI flash content, and xdc file.

Be sure to follow the noddr procedure in Xilinx SDK

Warning

• Use as your own risk but feel free to ask me if any problem
• My testings are not sufficient
• No DDR or PS-side IO so the ARM cores are literally useless except booting from QSPI flash
• Using ingenuine JTAG downloader may have legal issue
• Electrostatic discharge should be taken care of -- it already has SMAJ5.0CA but who knows?
• Contains lead(Pb)
• It's a 4-layer so all common PCB design rules are put aside, signal integrity compromised

Gallery

• Front view

  with ymmcu-ft2232 and w5500-lite, thanks USTCLUG for the sticker

• Back view

• ILA showing some assembly loaded from SD card running on RISC-V core in PSRAM

Misc.

About the name

https://nethackwiki.com/wiki/Trap#Squeaky_board

Reference

• Mainly UG933, some UG483 and UG585
• Testing files from Digilent and fpga4fun

Cooperation

I made one batch(5 pcs), 4 are soldered and 1 is left abandoned. Among the 4, 1 was sold, 1 was given to friend, and 2 are in my hands. If anyone want to make the board again using the PCB files, please contact me. I'll fix the UART bug, export Gerber if needed, and maybe mail you my excess components.