SL6087 and USB connection

Hi All!

I have a question about USB interface on SL6087 (firmware 7.45.1).

I have assembled the board with SL6087 and have connected USB to the SL6087 usb port as described in tech breef.
But i have no response from this usb. It looks like USB not working at all. Examples not working too. In examples USB init returns -1 when i try to initialize driver on SL6087.

How the normal usb connection have to behave usualy? Shal it register on PC when i connect USB cable? Or my be it shell open USB uart?


Hi Dmitry,

Have you tested your SL6087’s USB interface on dev.kit?

What is your host platform?

Can you check if the USB interface was already enabled?
To check if USB is enabled, please send:
To enable USB interface:


Thank you Lotam,

The host platform is Win7 64 bit and i use my own board. Now Win7 try to search for driver but then return error 43 (unknown driver).
I have check the USB and it is enabled.
I think i have problems with an hardware. It is possible that i have demaged the SL6087 inputs.

Thanks for the answers,


I also have a problem with USB in SL6087. I use my own board with embedded linux 2.6.21.
Software version is:R7.43.0.A1
SL is in default fast idle mode.
D- is always near 0 V

I don’t see SL6087 enumeration in system. I also can’t see any transfer on D+,D- pins. It seems like SL6087 is not detected.
I can enable USB with
D+ goes to 0,09 V

D+ shrinks to 0,01 V

  1. Are those Values correct - D+ seems to low for me ?
  2. How can I check if VPAD-USB is HIgh ? (How to read this input)
  3. Are there any other AT commends to check USB state

Thank you for your answers,
Bartlomiej Grzeskowiak

For test result on Win7, just wonder if you have the driver installed correctly?