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<?xml-stylesheet type="text/xsl" href="https://community.arm.com/utility/feedstylesheets/rss.xsl" media="screen"?><rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:slash="http://purl.org/rss/1.0/modules/slash/" xmlns:wfw="http://wellformedweb.org/CommentAPI/"><channel><title>LPC 2129 3.3 Vdda not connected</title><link>https://community.arm.com/developer/tools-software/tools/f/keil-forum/40128/lpc-2129-3-3-vdda-not-connected</link><description> 
I have designed a pcb to run the LPC 2129 in the LQFP64(64 pin)
package. As the system was too congested i decided to skip the 3.3
Vdda connection believing it to be required only for the ADC as a
reference voltage. 
But the problem now is than on the</description><dc:language>en-US</dc:language><generator>Telligent Community 10</generator><item><title>RE: LPC 2129 3.3 Vdda not connected</title><link>https://community.arm.com/thread/140543?ContentTypeID=1</link><pubDate>Thu, 28 Mar 2013 03:18:37 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:3e8f06e4-e97c-4926-9513-5cf44fb475ce</guid><dc:creator>Jason Fernandes</dc:creator><description>&lt;p&gt;&lt;p&gt;
Thanks fr the support it was a PCB error after all.&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: LPC 2129 3.3 Vdda not connected</title><link>https://community.arm.com/thread/136983?ContentTypeID=1</link><pubDate>Thu, 28 Mar 2013 01:28:40 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:917a5c30-4ba2-4f04-a7d2-61c7fd9024d8</guid><dc:creator>ImPer Westermark</dc:creator><description>&lt;p&gt;&lt;p&gt;
Then you have a number of alternatives to consider.&lt;br /&gt;
- you have broken the hardware&lt;br /&gt;
- your software is buggy (like having selected wrong multiplexing for
CAN2 pins)&lt;br /&gt;
- you have missed to turn on power for CAN2 - or does it too late in
the code&lt;br /&gt;
- you have a PCB error (beside the Vdda error)&lt;br /&gt;
- ...&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: LPC 2129 3.3 Vdda not connected</title><link>https://community.arm.com/thread/128103?ContentTypeID=1</link><pubDate>Thu, 28 Mar 2013 00:57:09 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:a8849385-ab61-42d4-8cc9-f6d4baa4c063</guid><dc:creator>Jason Fernandes</dc:creator><description>&lt;p&gt;&lt;p&gt;
Applying 3.3 Vdda did not make a difference&lt;br /&gt;
it still doesnt work&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: LPC 2129 3.3 Vdda not connected</title><link>https://community.arm.com/thread/120005?ContentTypeID=1</link><pubDate>Thu, 28 Mar 2013 00:49:39 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:cab8cf16-ad91-47b8-b07b-c1ae5c6aad05</guid><dc:creator>Andy Neil</dc:creator><description>&lt;p&gt;&lt;p&gt;
The Datasheet/User Manual tells you what you &lt;b&gt;must&lt;/b&gt; do for
the device to work as specified. If you deviate from those
instructions, the behaviour is &lt;i&gt;&lt;b&gt;undefined&lt;/b&gt;&lt;/i&gt;.&lt;/p&gt;

&lt;p&gt;
&lt;i&gt;&amp;quot;my delimma is HOW is CAN1 working in all of this ?&amp;quot;&lt;/i&gt;&lt;/p&gt;

&lt;p&gt;
That&amp;#39;s really not a question to worry about; the behaviour is
&lt;b&gt;undefined&lt;/b&gt; - so &lt;i&gt;&lt;b&gt;anything&lt;/b&gt;&lt;/i&gt; can happen!&lt;/p&gt;

&lt;p&gt;
As already suggested, apply the 3V3 correctly and see what
happens...&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: LPC 2129 3.3 Vdda not connected</title><link>https://community.arm.com/thread/106978?ContentTypeID=1</link><pubDate>Wed, 27 Mar 2013 21:22:28 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:c6a6fa42-aa52-44ed-ad4b-47bf69242f72</guid><dc:creator>Jason Fernandes</dc:creator><description>&lt;p&gt;&lt;p&gt;
Guess it was a beginer&amp;#39;s mistake just that I wanted to minimise
the number of connections to the IC as the board size i&amp;#39;m using is
quite limited. There is no real mention of the use of the 3.3 Vdda
other tha n a reference to the ADC but my delimma is HOW is CAN1
working in all of this ? but not CAN2 . Shouldn&amp;#39;t both not work even
the UART for that matter. UART is also working fine.&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: LPC 2129 3.3 Vdda not connected</title><link>https://community.arm.com/thread/92261?ContentTypeID=1</link><pubDate>Tue, 26 Mar 2013 13:04:05 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:47c6caa1-1cd2-4a3d-9495-2dfa9f777384</guid><dc:creator>Westonsupermare Pier</dc:creator><description>&lt;p&gt;&lt;p&gt;
I scanned the user manual and could find anything suggesting
anything else is on the VDDA/VSSA domain, not the CAN, not a
Power-On-Reset (which would kill you on an STM32 BTW). I wouldn&amp;#39;t had
let it float, but can appreciate a beginner might. Not everyone is
infallible.&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: LPC 2129 3.3 Vdda not connected</title><link>https://community.arm.com/thread/92263?ContentTypeID=1</link><pubDate>Tue, 26 Mar 2013 08:16:44 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:14c2d583-4eda-4c90-b512-4e0228a5c5c2</guid><dc:creator>Westonsupermare Pier</dc:creator><description>&lt;p&gt;&lt;p&gt;
From the user manual UM10114:&lt;/p&gt;

&lt;p&gt;
Remark: When the ADC is not used, the VDDA pin must be connected
to the power supply&lt;br /&gt;
VDD(3V3), and pin VSSA must be grounded. These pins should &lt;b&gt;not&lt;/b&gt;
be left floating.&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: LPC 2129 3.3 Vdda not connected</title><link>https://community.arm.com/thread/61791?ContentTypeID=1</link><pubDate>Tue, 26 Mar 2013 08:09:29 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:f2bd66d4-c1bc-4ff1-b09a-c1faa2dd6e48</guid><dc:creator>Westonsupermare Pier</dc:creator><description>&lt;p&gt;&lt;p&gt;
Connect a wire to the pin to get 3V3 there, problem either
confirmed, or not, and you can go look at your code. Estimated time
to perform 5 minutes, complexity low.&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item></channel></rss>