[SI-LIST] Re: DDR interface
- From: "Fraiman, Edi" <Edi.Fraiman@xxxxxxxxxx>
- To: "Karthik Raj" <karthikraj.g@xxxxxxxxx>, <si-list@xxxxxxxxxxxxx>
- Date: Tue, 26 Sep 2006 10:34:27 -0400
Hi,
Yes you right. Actually JEDEC specify relatively wide range : from 75%
to 125% of clock cycle.
Best regards,
Edi Fraiman
-----Original Message-----
From: Karthik Raj [mailto:karthikraj.g@xxxxxxxxx]
Sent: Tuesday, September 26, 2006 10:30 AM
To: Fraiman, Edi
Subject: Re: [SI-LIST] DDR interface
Hi,
I am not very sure about DDR but in DDR2 there is a spec that
determines the CLK - DQS relation called tDQSS. You may need to make
sure that your lengths meet this timing.
Rgds,
Karthik
On 9/26/06, Fraiman, Edi <Edi.Fraiman@xxxxxxxxxx> wrote:
Hi all,
I have question about DDR interface layout.
I understand that during PCB layout the DQS (data
strobe) should be
routed with same length as DQ (data), DQM signals and
Address bus and control signals (RAS,CAS, CKE,WE,CS)
should be aligned
to clock.
But I do not understand what relationship (what the
maximum difference
in length) between DQS and CLOCK.
Could you please advise?
=20
Best regards,
Edi Fraiman
=20
=20
=20
- - - - - Appended by Scientific Atlanta, a Cisco
company - - - - -=20
This e-mail and any attachments may contain information
which is confidenti=
al, proprietary, privileged or otherwise protected by
law. The information =
is solely intended for the named addressee (or a person
responsible for del=
ivering it to the addressee). If you are not the
intended recipient of this=
message, you are not authorized to read, print, retain,
copy or disseminat=
e this message or any part of it. If you have received
this e-mail in error=
, please notify the sender immediately by return e-mail
and delete it from =
your computer.
------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the
Subject field
or to administer your membership from a web page, go to:
//www.freelists.org/webpage/si-list
For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject
field
List FAQ wiki page is located at:
http://si-list.org/wiki/wiki.pl?Si-List_FAQ
List technical documents are available at:
http://www.si-list.org
List archives are viewable at:
//www.freelists.org/archives/si-list
or at our remote archives:
http://groups.yahoo.com/group/si-list/messages
Old (prior to June 6, 2001) list archives are viewable
at:
http://www.qsl.net/wb6tpu
- - - - - Appended by Scientific Atlanta, a Cisco company - - - - -
This e-mail and any attachments may contain information which is confidential,
proprietary, privileged or otherwise protected by law. The information is
solely intended for the named addressee (or a person responsible for delivering
it to the addressee). If you are not the intended recipient of this message,
you are not authorized to read, print, retain, copy or disseminate this message
or any part of it. If you have received this e-mail in error, please notify the
sender immediately by return e-mail and delete it from your computer.
------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
or to administer your membership from a web page, go to:
//www.freelists.org/webpage/si-list
For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
List FAQ wiki page is located at:
http://si-list.org/wiki/wiki.pl?Si-List_FAQ
List technical documents are available at:
http://www.si-list.org
List archives are viewable at:
//www.freelists.org/archives/si-list
or at our remote archives:
http://groups.yahoo.com/group/si-list/messages
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
Other related posts:
