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Message
From: M. AbuKhater<perocletos@y...>
Date: Wed Apr 14 10:09:25 CEST 2004
Subject: [usb] 2.0 Hub
hi ravi
that was really helpfull, thankx for the fast reply.
two more things, 1. is this applicable for full-speed hub and several low-/full-speed devices?
2. for low speed devices, baud rate is the same as bit rate (i.e. 1.5M), is that right?
regards
Abukhater
Ravi Rajaraman <ravi_prr2000@h...> wrote:
Hi Abu,
Assume the following scenario.Host and hub(high speed).
Host ---> Hub -------> Dev1 (full)
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|-------------> Dev2 (low)
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--------------> Dev3 (full)
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|--------------> Dev4(low).
In this case if a full speed transfer comes from the host,the hub decodes the split and
sends that transfer to all the enabled downstream full speed ports ie dev1 and dev3.
similar is the case for low speed.
One point here is, all enabled downstream ports,keep that in mind.
Regards,
Ravi
----- Original Message -----
From: M. AbuKhater
To: Discussion list about free, open source USB IP core
Sent: Monday, April 12, 2004 11:14 PM
Subject: Re: [usb] 2.0 Hub
hello ravi
so I suppose that packets directed to a full-/low-speed device are broadcasted to all full-/low-speed devices connected to it, is that right?
Abukhater
Ravi Rajaraman <ravi_prr2000@h...> wrote:
Hi Abukhater,
A high speed host communicates with a high speed device only in high speed.
It would be of much use to you if you could study split transfers.It is via the split
transfers that the high speed host communicates with a full/low speed device
under the hub.The hub is responsible to properly decode the split transfers and
redirect the transfers to the appropriate port. The hub at this point acts as a full/low speed
host to the full/low speed device connected to it.
Regards
Ravi Rajarman
----- Original Message -----
From: M. AbuKhater
To: usb@o...
Sent: Sunday, April 11, 2004 2:08 PM
Subject: [usb] 2.0 Hub
happy easter all;
lets say a USB2.0 hub is connected to a host , with many high-, full- and low-speed devices connected to it.
as indicated in the USB system architecture , a full speed packet is heared only by full speed devices , same for low- high-speed devices.
does this mean that the host sends low and full speed frames to high speed hub?
if not how does the hub knows which packet is should go to which device?
thanks
Abukhater
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