USB Client and USBH_PEN pin

Technical Support
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1

In this topic I got info on how to disable USB Host functionlity on Colibri VF61 with Win CE 6.

  • remove SODIMM 137 jumper, USB_C_DET related circuitry
  • set SODIMM 137 as GPIO output and 1
  • set registry as shown in below
[HKEY_LOCAL_MACHINE\Drivers\BuiltIn\UFN]
"Dll"="usbfn.dll"
[HKEY_LOCAL_MACHINE\Drivers\BuiltIn\USBOTG]
"Dll"="_otg_vybrid.dll"

If I don’t need Host functionality, can I use SODIMM_129 (which is USBH_PEN for Colibri family) as a general purpose INPUT?

I configured in this way in the bootloader, but with an oscilloscope it seems that Win CE reconfigures it as a low output (standard behavior for USBH_PEN, I think).

Should I set something else on WinCE side?

2

Dear @vix
The USBH_PEN pin (SODIMM_129) is controlled by the USB host driver. To prevent the driver from reconfiguring the pin, you need to disable this driver:

[HKEY_LOCAL_MACHINE\Drivers\BuiltIn\HCD_HSH1] 
"Dll"="_hcd_hsh1.dll"

Currently the USB host driver is hard coded to use SODIMM_129 as a power enable pin. If you need to use the USB host port, but use SODIMM_129 as an input, we need to implement a configuration feature into the USB host driver to allow using another GPIO for the power-enable functionality.
Regards, Andy