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12 KiB

ULX3S Manual

Connectors

US1    Main micro-USB for power, program and communication.
       All onboard hardware can be programmed or reconfigured
       over US1: FPGA, FLASH, WiFi, RTC.

US2    Auxiliary micro-USB connected directly to FPGA pins
       for experimenting with user-defined USB cores.
       Board provides power to US2.
       Board v1.7 can't be powered from US2 by default.
       Board v2.0 and higher can be powered from US2-
       If you want to power board v1.7 from US2, reverse diode
       D9 near US2 connector or short D9 with a wire.

GPDI   Plug for cable to digital monitor or TV,
       4 TMDS+- video
       1 HEAC+- ethernet and audio return 
       SDA,SCL  I2C (DDS EDID)
       CEC      remote control
       +5V      supply to enable plug-in detection

AUDIO  3.5 mm jack with 3 channels for earphones
       and digital audio or composite video (analog TV)
       Suitable cables are 3.5mm to 3-RCA (cinch)
       Red-White-Yellow for iPhone/iBook/NOKIA.
       Sony cables are the most popular and look identical
       but are not suitable, they have GND at Ring2!
       Tip:    Left analog audio
       Ring1:  Right analog audio
       Ring2:  Digital audio SPDIF
       Sleeve: GND

OLED   7-pin 2.54 mm header OLED1 for SSD1331 SPI color OLED
       pinout:   CS DC RES SDA SCL VCC GND

JTAG   6-pin 2.54 mm header J4 for external JTAG programmer
       pinout:   3V3 GND
                 TCK TDI
                 TDO TMS

GPIO   40-pin 2.54 mm double-row connectors J1 and J2 for GPIO 
       at 3.3V logical level with 56 pins from which are:
       J1 GP,GN 0-7 are single-ended pins.
       J1 GP,GN 8-13 are differential bidirectional pairs.
       J2 GP,GN 14-21 are differential bidirectional pairs.
       J2 GP,GN 22-27 are single-ended pins.
       Differential pairs can be used also as single-ended pins.
       J1 GP,GN 12 is differential primary clock capable.
       J1 GP,GN 0,1 are single-ended primary clock capable.
       J1 GP 13 and J2 GN 17 are general routing (non-primary)
       clock capable.
       J1 pins GP,GN 9-13 are shared with WiFi on PCB v1.7.
       J1 pins GP,GN 11-13 are shared with WiFi on PCB >v2.0.
       J2 pins GP,GN 14-17 are shared with ADC.
       4 PMOD connectors can be made out of it
       (GND and 3.3V power are on the right place)
       J1-J2 distance is suitable to be plugged into triple
       protoboard using a single row of J1/J2.      
       J2 has also 5V IN/OUT (be careful, GPIO pins are not
       5V tolerant).

SD     Micro SD card, all signal pins are routed to FPGA and
       shared with ESP-32

ESP32  Placeholder to solder ESP-32 WROOM module.
       ESP-32 can provide standalone web interface for uploading
       bitstream into FPGA and its config FLASH. 
       Warning on PCB v1.7 ESP-32 must be isolated from all SD
       card pins otherwise ESP-32 won't boot no matter if
       SD card is inserted or not.

Constraints (board pinout)

For PCB v1.7 patched for ESP32 to work

For PCB v2.x.x and v3.0.x

Power

Plug US1 into PC or USB charger and board should power up.

Initial voltage rise at USB 5V line will trigger board powering up and holding the power.

USB-serial chip FT231X will always be powered from 5V USB on PCB v1.7. The board has switching voltage regulators which can be turned off to reduce power consumption.

Green LED D18 behaviour is the "Power LED". Green LED ON will keep board powered up. By factory default, when USB-serial chip is enumerated by PC, Green LED will turn ON. Normally when board is plugged into USB charger Green LED may shortly blink and stay OFF, but board will keep being powered.

Board PCB v1.7 must be hardware patched to be able to reliably enter shutdown mode. (It will keep waking up).

RTC without battery will keep powering up the board as factory default. 3V battery CR1225 and configured RTC chip is required for the board to enter shutdown mode. There are several ways to wake up the board:

1) Press BTN0
2) Re-plug US1 micro-USB cable
3) RTC ALARM (using MCP7940N or PCF8523 arduino example)
4) Turn on Green LED D18 (using ftx_prog or libftdi)

Just a short pulse at RTC (ALARM INT1 shorly pull down) or Green LED shortly going HIGH is enough to wake up the board.

There is SHUTDOWN pin where FPGA can turn OFF the board. This pin is not correctly routed on PCB v1.7 and needs hardware upgrade to make it work.

On J2 connector there are 2 pins for 5V external power input and output. They are located on top right, near pin labeled 27 and US2 connector. Power is unidirectionaly routed using schottky diodes.

Powering only from 3.3V is not possible because switching regulators need 5V to generate 2.5V and 1.1V.

Switching regulators use ferrite core coils L1,L2,L3 which can saturate at magnetic fields above 0.3T. Never approach neodymium magnets near powered board.

Programming over USB

Use ftx_prog to allow max USB power consumption of 500mA and change product/manufacturer name of FT231X chip:

ftx_prog --max-bus-power 500
ftx_prog --manufacturer "FER-RADIONA-EMARD"
ftx_prog --product "ULX3S FPGA 45K v1.7"

Optionally you can change "45K" to "25K" or "12K" in regard with FPGA chip size. Re-plug the USB and it will appear as new name which can be autodetected with USB-serial JTAG tool.

To program ULX3S, Use ujprog or Emard's fork of Xark's FleaFPGA-JTAG tool or ft232r driver in latest OpenOCD.

"ujprog" tool acceps BIT or SVF files for uploading to the FPGA SRAM. Upload to onboard FLASH can't be yet done by "ujprog"

ujprog bitstream-sram.bit
ujprog bitstream-sram.svf

"FleaFPGA-JTAG" tool accepts VME files for uploading to the FPGA SRAM or onboard SPI FLASH chip. SRAM VME file is simple to make, but when generating FLASH VME file, follow the Lattice TN02050 document: "Programming External SPI Flash through JTAG for ECP5/ECP5-5G" section: "6. Programming the SPI Flash with bitstream file using Diamond Programmer" and select FLASH chip type:

Family: SPI Serial Flash
Vendor: Micron
Device: SPI-M25F32
Package. 8-pin VDFPN8
Verify: No

When it creates VME file, pass it to FleaFPGA-JTAG argument. Disabled "verify" will make flashing fast, but if enabled, expect to wait 5-15 minutes. Verify is normally not neccessary because bitstream has CRC.

FleaFPGA-JTAG bitstream-flash.vme

"OpenOCD" tool accepts SVF files and can upload to SRAM or onboard FLASH. For details see their documentation.

Programming over JTAG header

Any openocd compatible JTAG like FT2232 can be connected to JTAG header and it will program SRAM and FLASH at maximum speed possible. Even Diamond programmer can use any FT2232 module as a native programmer, with a little help - it will work after first bitstream is programmed over FT2232 with openocd.

Openocd accepts SVF files, everything applies the same as for VME files

ddtcmd -oft -svfsingle -revd -if ulx3s_flash.xcf -of bitstream.svf

Programming over WiFi

ESP-32 provides standalone JTAG SVF player over web HTTP and TCP interface for programming and flashing in convenient and OS independent way. Web interface requires no client software installed but web browser. It is much faster than FT231X but still not as fast as FT2232. It accepts SVF files but you need to limit SVF command size to max 8 kilobits "-maxdata 8", effectively it will split upload into many shorter SVF commands because ESP-32 doesn't have enough memory to buffer entire bitstream delivered in a long single SVF command.

ddtcmd -oft -svfsingle -revd -maxdata 8 -if ulx3s_flash.xcf -of bitstream.svf

To start using ESP-32 first you need to compile ULX3S passthru and upload it using FleaFPGA-JTAG or external JTAG programmer. "Passthru" bitstream configures FPGA to route lines from USB-serial to ESP-32.

Then you need to install Arduino and its ESP-32 support, and install Emard's library LibXSVF-ESP, required library dependencies and ESP-32 SPIFFS uploader Version "ESP32FS-v0.1.zip" worked for me.

In Arduino boards manager select this ESP-32 board:

DOIT ESP32 DEVKIT V1

Select "Examples->LibXSVF->websvf" and optionally change its default ssid/password. Compile and upload the code by clicking "Sketch->Upload", check reports on lower terminal window, successfull upload will finish with this:

Hash of data verified.
Leaving...
Hard resetting...

Then upload the web page content to ESP-32 FLASH filesystem, at websvf window click "Tools->ESP32 Sketch Data Upload". successful upload will finish with same as above.

Connect to ESP-32 WiFi (it will either connect to your local WiFi or become access point with default ssid=websvf password=12345678).

In web browser open upload page "http://192.168.4.1". If ESP-32 connected as a client, IP address will vary depending on local network. Discover it by using WiFi access point web interface, ARP, NMAP, or by sniffing it. On the ESP-32 page something like this will appear:

  Select SVF File or use minimal or svfupload.py
  [File] File not selected
  [Upload]
  [0%              ]

Navigate file selector to bitstream.svf file, it will show its size in KB. Then click "Upload", progress bar will run from 0% to 100% in few seconds (if it's SRAM upload) and bitstream will be started. FLASH can also be written from web iterface it takes 2-3 minutes. Also on the web interface there's available for download a small python commandline upload tool.

Note that FPGA can enable or disable ESP-32 module. If ESP-32 is disabled by newly uploaded bistream, some alert window will pop-up after otherwise successful upload because ESP-32 cannot close HTTP session properly. To make it go smooth, in the bitstream make FPGA pin "wifi_en" as input (HIGH-impedance, pull up).

Technically, ESP-32 can be loaded with such a code that permanently holds JTAG lines while FPGA can at the same time have in FLASH a bitstream that permanenly enables ESP-32. Such combination will preventing JTAG from working so ULX3S board may become "Bricked". There is jumper J3 to disable ESP-32, its left of SD card slot. Note boards PCB v1.7 need upgrade for this jumper to work correctly.

Board Versions

This project is open source, freely downloadable so there can be as many versions as here are git commits.

v3.0.3 is currently the only version which is officially being sold at skriptarnica. Other versions are either prototypes or independently produced.

Up to our knowledge those versions are currently circulating around. All listed versions should work if all parts (notably BGA) are properly soldered.

PCB       assembly       quantity                constraints
version   facility       produced   date         compatibility   note
-------   ------------   --------   ----------   -------------   --------
v1.7      PCBWay         8          dec 2017     v17patch        prototype
v1.7      lemilica.com   1          jan 2018     v17patch        handwork
v1.8      PCBWay         10         may 2018     v18             prototype
v2.0.3    q3k            1          aug 2018     v20             handwork
v2.1.2    INEM-KONČAR    35         sep 2018     v20             prototype
v3.0.3    INEM-KONČAR    220        oct 2018     v20             for sale
v2.0.5    Marvin         1          nov 2018     v20             handwork
v3.0.3    INEM-KONČAR    35         jan 2019     v20             for sale