Tang Primer 20K

Update history
Date Version Author Update content
2022-08-25 v0.1 wonder
  • Init docs


Tang Primer 20K is a core board with DDR3 sodimm shape based on GW2A-LV18PG256C8/I7 as the main chip, with 2 ext-boards are prepared, the Dock and the Lite.

Buy it: Aliexpress


Item Parameter Addition
FPGA Chip GW2A-LV18PG256C8/I7
Logic units(LUT4) 20736
Flip-Flop(FF) 15552
Shadow SRAM S-SRAM(bits) 41472
Block SRAM B-SRAM(bits) 828K
Number of B-SRAM 46
18x18 Multiplier 48
PLLs 4
I/O Bank 8
Memory 128M DDR3
Flash 32Mbits NOR Flash Read burn Flash
Debugger Jtag + Uart JST SH1.0 8Pins connector
SD card slot 1 Push-pull type
Display 8Pins spi lcd connector
Package 204P DDR3
Avaliable IO 117

Comparison between ext-board

Dock ext-board appearance

The corresponding pins numbering of LED2 and LED3 is N16 and N14. See the mark on left of the right picture.

dock-up dock-back

Lite ext-board appearance

The corresponding pin numbering between R8 and P9 is P8. See the mark on the top left of the right picture.

lite-up lite-back

Comparison between peripherals of ext-board

Item Dock Lite
Number Addition Number
RGB Interface 1 RGB565 40P FPC Connector
DVP Interface 1 24P FPC Connector
Mic array Interface 1 10P FPC Connector
Touch Interface 1 6P FPC Connector
PMOD Interface 4 4
3.5mm headphone Jack 1 LPA4809MSF driver
DIP switch 1 5P DIP switch
Slide switch 1 Switch USB function 2
Type-C USB-JTAG&UART 1 Onboard BL702 used to download bitstream file and provide serial communication
User-defined USB 1 USB3317 with Slide switch to change USB Interface function
Wireless antenna 1 BL702 wireless function
Key 6 One used for burning BL702,
five for Users
HDMI Interface 1
Ethernet Interface 1 RTL8201F
RGB LED 1 WS2812

Hardware information

User guide

Install IDE -> Learn coding programmer -> Read Tutorial -> Program by yourself -> Read more official documents

  1. Install IDE: Click me.

  2. Visit Start to use to avoid some problems, and we can start coding for FPGA there.

  3. After coding for FPGA, if you think it difficult, here we collect some useful learning resource.

    If you have trouble using IDE, we have packed all documents about IDE, visit Download station and download what you need.

Reference examples summary


github :https://github.com/sipeed/TangPrimer-20K-example



Additional message

The default bank voltage of bank 0、bank 1、bank 7 on the core board is 3.3V, so their bank IO voltage is 3.3V output. If you want to custom the input IO bank voltage, please remove R5 and R9, see Assembly Click me to see where is R5 and R9.


And the corresponding golden finger on core board are as following:



Dock ext-board not work

For 20K Dock kits, it's necessary to enable the core board before using debugger debug the chip, just put the 1 switch on the dip switch down, otherwise LED0 and LED1 are on and core board dose not work.

Enable Core Board Disable state Additional comments
switch_1_on reset_led_on When disabled, the LDE0 and LED1 is on, and core board doesn't work.

How to burn into flash

Do following configurations:


No reaction after burning or phenomenon is wrong

Make sure you hace selected right device, and all parameters are the same as following.


Then make sure your code logic is right and your

Successfully burned once, but can't burn after that

Note that the description is there was a successful Flash burnt one time.

In this case, the default reason is that the wrong Dual-Purpose pin is enabled and the debugger can no longer scan the FPGA's JTAG. You can short pin 1 and pin 4 of Flash, by which the chip cannot read FLASH normally when it is powered on.


Besides, if you have dock ext-board, this can be solved by the enable pin of dip switch. Here art the steps

Firstlt, enable the core board, put the 1 switch on the dip switch down, then do something (like burnning fpga or erasing FPGA) in Programmer application, when the progress bar shows, switch the 1 switch on the dip switch up and down, after which you will find the progress bar works and finish your operations on fpga.

switch_1_on Enable the core board first
progress_bar Do operation on board, when progress bar shows, switch the 1 switch on the dip switch up and down
switch_1_off switch_1_on put the 1 switch on the dip switch up and down
progress_bar_runningprogress_bar_finishing Progress bar works and finish your operations on fpga

Visit Questions for more