M2X M.2 key B full speed support

dgel27 · September 8, 2022, 4:49pm

Hello,
Do you plan to produce M2X with full speed M.2 key B slot.

Currently on all 3 M2X boards on the M.2 B route only USB2 lines, so with these speeds possible reach only 5-10% of 5G modems speeds (QUCTEL RM500x and TELIT FN980)

Is it possible to use on VIM3, VIM4 boards full speed with USB3.1 and PCIe for M.2 B slot?

Thanks

numbqq · September 9, 2022, 9:41am

Hello @dgel27

5G module is based on PCIe not USB.

dgel27 · September 11, 2022, 7:54am

Hi,
Thanks for the answer. Is this is a “M2X WWAN Extension” adapter?
I have already ordered it, but i cannot find schematics for it on the web. Could you upload it?

Thanks,
Dmitry

lxmyzf · September 12, 2022, 12:17pm

the doc said ,the usb is usb 3.0.

github.com

khadas/khadas_docs/blob/master/linux/source/vim3/PcieUsbPort.md

title: PCIe/USB3.0 Port
---

Khadas VIM3 contains a 2:1 data switch chipset to switch the "combo interface" between `PCIe` and `USB 3.0`, and the default mode is `USB 3.0`.
You can refer the block below for further details:

![VIM3 PCIe/USB3.0 Block](/linux/images/vim3/vim3_pcie_usb3_block.png)

There are three ways to setup the `PCIe/USB3.0` port:
* Setup the port using the [KBI](KbiGuidance.html)
* Setup the port using the Ubuntu command line

## Setup the PCIe / USB3.0 port using the KBI
You need to [setup the serial debug tool](SetupSerialTool.html) and enter the u-boot command line.

* Initialize the KBI:

```sh
kvim3#kbi init
```

This file has been truncated. show original

and for the quectel RM500Q, if it works in pciemode, you can use the pcie-mhi driver .

dgel27 · September 12, 2022, 1:36pm

Hi lxmyzf,

You explain about VIM3, it’s ok, the CPU have these possibilities.

But it depend on which lines come to the modem. I have look in M.2 adapter schematics and found that only pins 7 and 9 routed to the modem. Pins 7 and 9 on the modem it regular D+ and D- of usb2 signals. With these lines and mode MIMO 4x4 the transfer speed to CPU will not reach 200M at all. It doesn’t matter what speed on the CPU side.

To work properly with 5G speeds, it need USB_SS* or PCIE* signals to be routed from CPU to the modem. In other way, there are not reason to order and use 5G modem at all.

I think the “M2X WWAN Extension” have these routes, but schematics isn’t published out.
I need these schematics to see other pins routing, because different modems have different additional signals (GPIO, PWR control, etc)

Thanks!