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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>Virtual Com Port Loopback runs w/o debugger not w/ debugger</title><link>https://community.arm.com/developer/tools-software/tools/f/keil-forum/32103/virtual-com-port-loopback-runs-w-o-debugger-not-w-debugger</link><description> 
Greetings, 

 
I&amp;#39;ve brought up the ST example VirtualComPort_Loopback (V4.0.0) on
a Keil demo board (MCBSTM32E vers3) and the Keil enviroment (uVision
4.71.2.0) connecting through the ST virtual comport driver (1.3.1.0)
and it works fine when not run</description><dc:language>en-US</dc:language><generator>Telligent Community 10</generator><item><title>RE: Virtual Com Port Loopback runs w/o debugger not w/ debugger</title><link>https://community.arm.com/thread/107341?ContentTypeID=1</link><pubDate>Wed, 04 Dec 2013 14:24:35 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:a02a7d60-5185-46c0-8cb3-e375a2789847</guid><dc:creator>Steve Stearns</dc:creator><description>&lt;p&gt;&lt;p&gt;
Thanks for your reply. The debugger is being run through the JTAG
(20 pin on the Keil board, 10 pin on my custom board) connected
through the ULINK2. The USB is identically wired on both the Keil
board (which I&amp;#39;m running) and the equivalent ST board. ST resells the
Keil board as part of their Keil starter kit offering for this
processor so one would hope it would work with their demos
&amp;lt;sigh&amp;gt;.&lt;/p&gt;

&lt;p&gt;
Nonetheless, the JTAG ports ARE wired a little differently
(something I had not looked at till your comment). On the Keil board
the 20 pin JTAG connector has pins 11, 17 and 19 open whereas on the
ST board they are all tied to ground via individual 10ks.&lt;/p&gt;

&lt;p&gt;
I don&amp;#39;t know enough about the generic JTAG interface nor the
unique-to-ST features to know if this is relevant or not. I have no
idea what affect these connections have on the ULINK2. However, it
surely doesn&amp;#39;t help with regard to my custom board as the 10 pin JTAG
interface on the ULINK2 does not include those connections. The 10
pin JTAG also does not support the TRS signal (PB4 on both the Keil
and ST demo boards).&lt;/p&gt;

&lt;p&gt;
Does this help you understand what&amp;#39;s going on? I&amp;#39;m still unclear
as to a means (other than what I&amp;#39;ve already done) to move
forward.&lt;/p&gt;

&lt;p&gt;
Thanks again,&lt;br /&gt;
Steve.&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: Virtual Com Port Loopback runs w/o debugger not w/ debugger</title><link>https://community.arm.com/thread/93072?ContentTypeID=1</link><pubDate>Wed, 04 Dec 2013 12:22:00 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:68ec821b-39d7-4f52-89c9-35d80bfd3fca</guid><dc:creator>Andy Neil</dc:creator><description>&lt;p&gt;&lt;p&gt;
How were you connecting the debugger to the board?&lt;/p&gt;

&lt;p&gt;
Did you compare the schematics of the Keil Board, and ST&amp;#39;s own
boards (which is, presumably, what they&amp;#39;d have had in mind when
making their USB stuff...)&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: Virtual Com Port Loopback runs w/o debugger not w/ debugger</title><link>https://community.arm.com/thread/62341?ContentTypeID=1</link><pubDate>Wed, 04 Dec 2013 10:59:12 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:d5cee07e-76c0-4249-be36-84eafdcd8604</guid><dc:creator>Steve Stearns</dc:creator><description>&lt;p&gt;&lt;p&gt;
Follow-up (may be useful for others with this problem): The best I
could do for a solution was to create different build targets for
stand-alone vs debugger differentiated by a #define and #ifdefs in
the code. The stand-alone version used the USB port as the
applications console when running without the debugger. When running
with the debugger, the application&amp;#39;s console was re-directed to the
ITM port and accessed by the debuggers &amp;quot;printf&amp;quot; window.&lt;/p&gt;

&lt;p&gt;
In other words, I was unable to find a way to run the debugger
that didn&amp;#39;t kill the USB virtual terminal connection.&lt;/p&gt;

&lt;p&gt;
As an aside, though I posted my question on both the Keil and ST
forums, I did not get any replies on either. &amp;lt;sniff..., was it
something I said?&amp;gt;&lt;/p&gt;

&lt;p&gt;
Steve.&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item></channel></rss>