[SI-LIST] Re: DDRII write problem!!
- From: Heyfitch <heyfitch@xxxxxxxx>
- To: TinaWu <tinawu@xxxxxxxxxxx>
- Date: Tue, 18 Aug 2009 23:05:15 -0500
To elaborate on my previous message, that may be too concise.....
Whenever the enable node is pulled so that the buffer is a driver, the
internal node "nd_out_of_in" becomes 0.5V - i.e. half way between the core
logic high and low. This makes me think that you may not be explicitly
controlling the EN node of the buffer and it flaps cack and forth between
high and low causing the buffer to alternate between being a receiver and a
driver. At the times when it's a driver, this node goes 0.5V.
- Vadim Heyfitch
On Tue, Aug 18, 2009 at 10:43 PM, Heyfitch <heyfitch@xxxxxxxx> wrote:
> Tina,
> the info you gave is not sufficient to unambiguously tell what the problem
> is. It is possible that you are not controlling 'enable' pin of the buffer
> on the DRAM model. You need to state appropriately to be receiving.
>
> Vadim
>
> On Tue, Aug 18, 2009 at 9:38 PM, TinaWu <tinawu@xxxxxxxxxxx> wrote:
>
>> Dear Sir,
>> I simulated the DDR write and the waveform is bad.
>> Here, I found the input(DQ) of DDR chip.
>> There are 3 states - logic 0 (0V)ã??logic 1 (1V) and
>> the other state 0.5V. Is the phenomena right??
>> Thanks in advance!!
>> BRs,
>> Tina
>> ------------------------------------------------------------------
>> 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
>>
>>
>>
>
------------------------------------------------------------------
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:
