[SI-LIST] Re: SDRAM Timing Help
- From: "Perrow, Shane" <Perrow@xxxxxxxxxx>
- To: "Jory McKinley" <jory_mckinley@xxxxxxxxx>, <si-list@xxxxxxxxxxxxx>
- Date: Thu, 20 Sep 2007 15:32:38 +1000
Thanks Jory.
It's not DDR so I guess the only difference may be;
tco_min =3D tsdSDOH
tco_max =3D clk_period - tsdSDOS
However, this suggests that when dropping the clk rate down to say 1MHz,
the tco_max becomes several hundreds of nS!!!
Shouldn't the tco_max parameter be independent of the clock rate?
Thanks again.
Shane.
-----Original Message-----
From: Jory McKinley [mailto:jory_mckinley@xxxxxxxxx]=20
Sent: Thursday, 20 September 2007 2:32 PM
To: Perrow, Shane; si-list@xxxxxxxxxxxxx
Subject: Re: [SI-LIST] SDRAM Timing Help
Hello Shane,
This is done to account for internal PLL jitter plus any skew. Assuming
double data rate (data output on every clock edge) your general tco
numbers:
tco_min =3D tsdSDOH
tco_max =3D 0.5*clk_period - tsdSDOS
Draw out a timing diagram to convince yourself.
-Jory
----- Original Message ----
From: "Perrow, Shane" <Perrow@xxxxxxxxxx>
To: si-list@xxxxxxxxxxxxx
Sent: Wednesday, September 19, 2007 7:52:07 PM
Subject: [SI-LIST] SDRAM Timing Help
Hi all,=3D20
I'm hoping someone can help.
I'm trying to determine some min and max trace lengths to provide a safe
setup and hold margin for a CPU-SDRAM interface.
My problem is that all timing analysis usually refers to the parameters
tco_min and tco_max, but in this case the CPU provides the SDRAM clock
(with an internal PLL).=3D20
The CPU does not specify tco parameters for SDRAM writes, it specifies
tsdSDOS and tsdSDOH, which are defined as "output setup and hold times".
On the timing diagram this indicates that data is setup before the clock
edge and held after the clock edge for a certain amount of time.
My question is - how do these parameters tsdSDOS and tsdSDOH correlate
to the standard tco_min and tco_max ????=3D20
Thankyou in advance :)
=3D20
IMPORTANT CONFIDENTIALITY NOTICE:
This E-mail (including any documents referred to in, or attached, to =3D
this E-mail) may contain information that is personal, confidential or =
=3D
the subject of copyright, privilege or other proprietary rights in favor
=3D
of Aristocrat, its affiliates or third parties. This E-mail is intended
=3D
only for the named addressee. Any privacy, confidence, legal =3D
professional privilege, copyright or other proprietary rights in favor =
=3D
of Aristocrat, its affiliates or third parties, is not lost if this =3D
E-mail was sent to you by mistake.
If you received this E-mail by mistake you should: (i) not copy, =3D
disclose, distribute or otherwise use it, or its contents, without the =
=3D
consent of Aristocrat or the owner of the relevant rights; (ii) let us =
=3D
know of the mistake by reply E-mail or by telephone (AUS +61 2 9413 6300
=3D
or USA 1-877-274-9661); and (iii) delete it from your system and destroy
=3D
all copies.
Any personal information contained in this E-mail must be handled in =3D
accordance with applicable privacy laws.
Electronic and internet communications can be interfered with or =3D
affected by viruses and other defects. As a result, such communications
=3D
may not be successfully received or, if received, may cause interference
=3D
with the integrity of receiving, processing or related systems =3D
(including hardware, software and data or information on, or using, that
=3D
hardware or software). Aristocrat gives no assurances in relation to =3D
these matters.
If you have any doubts about the veracity or integrity of any electronic
=3D
communication we appear to have sent you, please call (AUS +61 2 9413 =
=3D
6300 or USA 1-877-274-9661) for clarification.
------------------------------------------------------------------
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 technical documents are available at:
http://www.si-list.net
List archives are viewable at: =20
//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
=20
Yahoo! oneSearch: Finally, mobile search that gives answers, not web
links.=20
IMPORTANT CONFIDENTIALITY NOTICE:
This E-mail (including any documents referred to in, or attached, to =
this E-mail) may contain information that is personal, confidential or =
the subject of copyright, privilege or other proprietary rights in favor =
of Aristocrat, its affiliates or third parties. This E-mail is intended =
only for the named addressee. Any privacy, confidence, legal =
professional privilege, copyright or other proprietary rights in favor =
of Aristocrat, its affiliates or third parties, is not lost if this =
E-mail was sent to you by mistake.
If you received this E-mail by mistake you should: (i) not copy, =
disclose, distribute or otherwise use it, or its contents, without the =
consent of Aristocrat or the owner of the relevant rights; (ii) let us =
know of the mistake by reply E-mail or by telephone (AUS +61 2 9413 6300 =
or USA 1-877-274-9661); and (iii) delete it from your system and destroy =
all copies.
Any personal information contained in this E-mail must be handled in =
accordance with applicable privacy laws.
Electronic and internet communications can be interfered with or =
affected by viruses and other defects. As a result, such communications =
may not be successfully received or, if received, may cause interference =
with the integrity of receiving, processing or related systems =
(including hardware, software and data or information on, or using, that =
hardware or software). Aristocrat gives no assurances in relation to =
these matters.
If you have any doubts about the veracity or integrity of any electronic =
communication we appear to have sent you, please call (AUS +61 2 9413 =
6300 or USA 1-877-274-9661) for clarification.
------------------------------------------------------------------
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 technical documents are available at:
http://www.si-list.net
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:
