Prev: LCD Monitor blank on first boot-up....
Next: Software RAID question
From: Matthias Koch on 17 Jan 2008 05:17
Dear Linux-Hardware-Freaks,

is there any possibility to directly access the usb D+/D- line drivers ?

After looking into the electrical specifications of the intel USB 1.1 document, I found out that there is a line driver with differential-one, differential-zero and SE0 - state, an output-enable and the controller includes one differential receiver and also two single-ended receivers for the D+/D- lines.

How may I control there features directly, it is possible to disable the hardware-implemented usb-protocoll, especially in the uhci 1.1 host controller chips ?

Best regards,
Matthias Koch
Germany
From: Clemens Ladisch on 17 Jan 2008 06:32
Matthias Koch wrote:
> is there any possibility to directly access the usb D+/D- line drivers ?

Not from software.

> How may I control there features directly, it is possible to disable
> the hardware-implemented usb-protocoll, especially in the uhci 1.1 host
> controller chips?

No. The most you could do is to use some feature from the USB
specification, e.g., you could tell the HC to apply suspend or reset
signaling to a port.

UHCI allow to read the level of the two data lines (bits 4, 5 in the
PORTSC registers), but these bits are only updated at the end of a
frame.


Regards,
Clemens
 | 
Pages: 1
Prev: LCD Monitor blank on first boot-up....
Next: Software RAID question