Gowin Analyzer Oscilloscope

TangNano-20K-example

• Clone the examples from the repository

git clone [email protected]:sipeed/TangNano-20K-example.git

FPGA Designer

• Start the Gowin FPGA Designer and load the project TangNano-20K-example/led/blink_led/blink_led.gprj

Analyzer Oscilloscope

• Create a GAO Config File from menu File > New > GAO Config File
• Choose the default Setting:
  • [o] For RTL Design
  • [o] Standard
• Keep the suggested GAO Name as blink_led
  • and the sub-directory to TangNano-20K-example/led/blink_led/src
  • button [Next >] will add src/blink_led.rao to the current project

Signals

• Back to the Design tree, double click the GAO file blink_led.rao

Trigger

• From the Trigger Options tab
• Double click Trigger Port 0
• Click (+) to add a signal
  • Click [Search] button to popup the Nets window
  • Select count_1s[23:0] and add it to the right panel with button [>]
  • Validate with [OK]
  • You will get count_1s[23:0] assigned to the Port 0
• In the middle column Match Units, double click the M0
  • You are in the Match Unit 0 where you select Trigger Port 0 from the drop-down box
  • With count_1s[23:0] selected, enter the decimal value 13500000
  • This matches condition in the Verilog code blink_led.v where ( count_1s < 27000000/2 )
  • Validate with [OK]
  • The match unit [x] M0 should be ticked
• In the right column, add an expression
  • In the empty panel, right-click mouse button to choose menu [Add]
  • In the Expression calculator, click button M0
  • Validate with [OK]
  • Expression M0 should be listed

Capture

• Choose the Capture Options tab
• Click the 3-dots buttons to assign a sample clock
• In the Nets popup window click [Search] to populate the left panel with signals
• Select clk and add it to the right panel with [>] button
• In the Capture Signals panel add two signals
  • [Search] for count_1s[23:0] and count_1s_flag
  • Click [>] to add both to the Capture Signals panel

Build

• The GAO is all set up, save it from menu File > "Save blink_led.rao"
• Back to the Process tree of the FPGA Designer, select Place & Route
• Right-click mouse button to choose Clean&Rerun All
• Accept to remove the previous results

Oscilloscope

• Plug the TN20K to the PC from its USB-C cable
• If ftdi_sio module present then unload it with sudo modprobe -r ftdi_sio
• Choose menu Tools > Gowin Analyzer Oscilloscope
• You should see all settings made so far:
  • exp0: M0 trigger expression
  • M0 match unit condition

Program fs

• Tick option [o] Enable Programmer
• Select the row which targets the GW2AR-18 device
• Click button to program the TN20k
• Once FPGA programmed, it will auto reset with the blink_led bitstream
  ...

Acquisition

• In green is displayed in the top bar [Ready to acquire]
• Click Play to start the acquisition: the ( > ) round blue button
• This will popup Oscilloscope window and the recorded signals