Efm32 Usb Cdc Serial Port Driver

Hi all, We have a USB product using an EFM32 CPU that normally appears as a USB Mass Storage device and does not require drivers. However, it uses the USB-CDC (USB serial port) configuration for special purposes such as firmware updates, and we may offer new products in the near future that use this in mainstream operation. What is the 'official' recommended way for (our) end-customers to get the CDC driver? It doesn't seem to be on e.g.

Windows Update, nor could I find a public download link on silabs.com. Based on some forum crawling, the only way to get it seems to be by fishing it out of a large dev tool download. Is it accepted/recommended to package a copy with our own software downloads., republish it on our own website and/or (as I believe the support folks have.actually. been doing), hand out dropbox.com links as needed?

Are there any near-future plans to make it available via Windows Update?. There's always a catch: There is an optional software tool that goes with the product, but it just unzips and runs and doesn't require 'installation', so it also doesn't present a good opportunity to preinstall Windows drivers. Note that you are not allowed to ship a product with the Silabs/EnergyMicro VID/PID pair, thus the default.inf file would be useless for any end user product. You will have to edit it - replacing the VID/PID with the correct numbers, and probably also the strings for the device that will show up in device manager.

I see no reason that should prevent you from shipping the edited.inf with your product, but IANAL. Windows versions up to 7 will allow installing an unsigned.inf file for a driver. Note that the composite CDC interface in the EFM32 example code will not work with windows XP SP2 and earlier, resulting in blue screen when used.

TurboJ wrote: Note that you are not allowed to ship a product with the Silabs/EnergyMicro VID/PID pair, Not allowed by whom? Last I checked, the USB-IF has no legal power over the use of VID/PID values, otherwise it would not be possible for SiLabs and other vendors to sublicense individual PIDs (as the USB-IF terms explicitly forbids this).

Efm32 Usb Cdc Serial Port Driver Windows 7

Given that the product contains a SiLabs Chip using the SiLabs bootloader, which comes pre-burned on the chip with the SiLabs VID/PID baked in, I don't suppose SiLabs would object to this scenario (although I would welcome an actual SiLabs employee chiming in on this). I don't suppose every vendor selling a product with a PL2302 or FTDI serial chip buys their own VID/PID, changes it on the chip and then pays to maintain their own Microsoft Digital Signature and WHQL certification on their custom-modified.inf text file, which they separately push to Windows Update?

TurboJ wrote: Windows versions up to 7 will allow installing an unsigned.inf file for a driver. Only the 32-bit versions, and not without protest at that. And again, we do not intend to enforce OS limitations on the customer over a silly text file if this can be avoided (say, by using the already signed text file that already exists). Drmn4ea wrote: TurboJ wrote: Note that you are not allowed to ship a product with the Silabs/EnergyMicro VID/PID pair, Not allowed by whom?

Rs232 Serial Port Driver

The Operating System (you know, like Windows). They use VID ID to assign drivers. This means you cannot change the USB descriptors to get rid of the component device, for example, as this may confuse the OS. You would need at least a new PID here. Note that libwdi shows a way to distribute an unsigned.inf file and install it in windows without any error or warning message. It generates the certificates on-the-fly.