QPCIe instructions

Hello Lime,

Today I tried to use the QPCIe board but I have some questions.

I connected the QPCIe board with a USB3.0 cable, but there is no led and the fan is not spinning. I saw a SW3 on the board, do I need to switch it on?

Will USB3.0 power supply be enough for this board or do I have to use the 12v power supply?

If I plug it on my computer using the pcie socket, will the pcie socket provide enough power?

And I saw an additional port called ANT which I have never seen on LimeSDR-USB, what does it stands for?

If I plug my amplifiers on the QPCIe board (especially LNA), is the max power the same as LimeSDR-USB? I want to make sure that I won’t damage this board.


Hi Shao,

You can find the documentation at:


Thanks Andrew,

I saw at Section 2.2.9 “The last supply source option is the board edge PCIe connector.” Does that mean I can simply power it up by pluging the board into PCIe slot?

The J38 6-pin Power connector is optional or compulsory? Is it the same as the 6pin connector of PCIe graphic cards?

The chapter 3 is a quick start menu for LimeSDR-USB, could you update it for QPCIe?

I can’t find a slot on my motherboard that is of the same shape of the QPCIe board.

My motherboard’s PCIe version is 3.0

What PCIe version is the QPCIe board using? Is it PCIe 3.0 or 4.0?

Hello @shao,

It is PCIe 1.0 which is backward compatible with PCIe 2.0 and up. It uses 4 lanes hence your mother board must have x4 PCIe slot (or bigger).


Thanks. My motherboard is PCIe 3.0 and with x8 and x16 slots, I think they will be compatible with PCIe 1.0 x4.

Yes, it is.

Great. Will try that. :grinning:

Hi Zack,

I am trying to use QPCIe in LimeSuite these days. But I found some problems. In LimeSuite 18.04, I can receive signals at LMS1 channel A and LMS2 channel A, but nothing for channel B, and when I hit the enable MIMO checkbox it crashes.

Then I tried it with LimeSuite 18.06, it doesn’t crash when I checked enable MIMO, but the signal I saw in FFT viewer isn’t real. It seems that FFT viewer is showing signal at frequencies I am not intend to.


Hi @shao,

What QPCIe board version do you have? What gateware version are you using?

FW:2 HW:0 Protocol:1 GW:1.1

The board version is v1.2

Hi @shao,

Try FPGA bitstream from the latest distribution package:

What version of LimeSuite should I use to update the FPGA bitstream to board?

Can I use LimeUtill --update to do that automatically?

I opened the onedrive link. It is a video file called gsm_demo.mp4?

Sorry, wrong link. Updated initial post with correct link.

Thanks, I will try to download it to my board tomorrow.

Hi Zack,

I downloaded the zip file today, there is a user guide inside. It’s written that I have to use USB 3.0 interface to upgrade the FPGA and power the board up through 12V external power supply?

And FX3 MCU has to be upgraded using cycontrol.exe? Can I upgrade it using LimeSuiteGUI like LimeSDR-USB?

Can I upgrade the FX3 MCU and altera FPGA through PCIe interface?


Hi @shao,

Correct. You have to power the board up if you want to update the firmware using LimeSuiteGUI or JTAG.

Both will work.


Can I use the board edge PCIe connector to power the board up while updating the firmware? I don’t have a reliable external 12V power supply and I don’t want to risk damaging the board. There is 3 options to power the board when using it normally, but for updating, will the other 2 powering methods be the same?

Is there a way that I can update its firmware and gateware without taking the board out from its pcie slot? Because it’s already in my server, it would take much effort to disassemble its brackets, etc. If the firmware/gateware updating has to go through USB3.0, can I connect the usb port to the computer while leaving the PCIe slot also connected with the board?


Hi @shao,

Yes, you can power up the board from PCIe slot when updating via USB.

This is how we do it usually:

  1. Power up the PC (#1) with LimeSDR-QPCIe board and stop booting by entering to BIOS;
  2. Use another PC (#2) connected to the LimeSDR-QPCIe board via USB cable to update firmware/gateware;
  3. Boot the PC #1 after update is finished.