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<p class=MsoNormal><a name=""><font size=2 color=navy face=Arial><span
lang=EN-GB style='font-size:10.0pt;font-family:Arial;color:navy'>Thanks</span></font></a><font
size=2 color=navy face=Arial><span style='font-size:10.0pt;font-family:Arial;
color:navy'> a </span></font><font size=2 color=navy face=Arial><span
lang=EN-GB style='font-size:10.0pt;font-family:Arial;color:navy'>lot</span></font><font
size=2 color=navy face=Arial><span style='font-size:10.0pt;font-family:Arial;
color:navy'>.<o:p></o:p></span></font></p>
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10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span lang=EN-GB
style='font-size:10.0pt;font-family:Arial;color:navy'>I guess this diagram also
solves the ISP upgrade failure problem, when AVR STUDIO says that ISP need
upgrade, - tries and fails on verify.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span lang=EN-GB
style='font-size:10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
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<p><font size=3 color=navy face="Times New Roman"><span style='font-size:12.0pt;
color:navy'>Med venlig hilsen / Best regards / mit freundlichen Grüßen</span></font><font
color=navy><span style='color:navy'><o:p></o:p></span></font></p>
<p><b><font size=3 color=navy face="Times New Roman"><span style='font-size:
12.0pt;color:navy;font-weight:bold'>EC POWER A/S</span></font></b><font
color=navy><span style='color:navy'><o:p></o:p></span></font></p>
<p><b><font size=3 color=navy face="Times New Roman"><span style='font-size:
12.0pt;color:navy;font-weight:bold'>Steven Lose</span></font></b><font
color=navy><span style='color:navy'><o:p></o:p></span></font></p>
<p><font size=3 color=navy face="Times New Roman"><span style='font-size:12.0pt;
color:navy'>Software Ingeniør<o:p></o:p></span></font></p>
<p><font size=3 color=navy face="Times New Roman"><span style='font-size:12.0pt;
color:navy'>Tlf.: +45 87434100<o:p></o:p></span></font></p>
<p><font size=3 color=navy face="Times New Roman"><span style='font-size:12.0pt;
color:navy'>Direkte tlf. +45 58286608<o:p></o:p></span></font></p>
<p><font size=3 color=navy face="Times New Roman"><span style='font-size:12.0pt;
color:navy'>Email: <a href="blocked::mailto:bsl@ecpower.dk">sl@ecpower.dk</a><o:p></o:p></span></font></p>
<p><font size=3 color=navy face="Times New Roman"><span style='font-size:12.0pt;
color:navy'><a href="http://www.ecpower.dk">www.ecpower.dk</a></span></font><o:p></o:p></p>
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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>Fra:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'>
icc-avr-bounces@imagecraft.com [mailto:icc-avr-bounces@imagecraft.com] <b><span
style='font-weight:bold'>På vegne af </span></b>John Baraclough<br>
<b><span style='font-weight:bold'>Sendt:</span></b> 12. marts 2007 17:57<br>
<b><span style='font-weight:bold'>Til:</span></b> Discussion list for ICCAVR
and ICCtiny Users. You do NOT need tosubscribe to icc-announce if you are a
member of this.<br>
<b><span style='font-weight:bold'>Emne:</span></b> Re: SV: [Icc-avr] SPI master
and slave</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Hi Steven,<br>
<br>
Our posts have crossed so there's a later one with a corrected diagram. The
resistor on RXD0 ensures that no signal on the RS232 receiver will interfere
with the ISP when it is operating. The value is sufficient to ensure isolation
but not large enough to interfere with normal operation when the ISP isn't
active.<br>
<br>
It's a simple trick that I picked up from one of the very early Atmel data
sheets. They don't put that particular diagram in the data sheets any more.<br>
<br>
There's a similar trick to be aware of when using SPI memory on AVR's that use
the SPI signals for programming. The SPI memory MISO signal can become active
when the chip select is floating during programming and it can cause a
programming failure. It needs either a 10k pull-up on the #CS line or a 1k
isolating resistor in the MISO line between the memory chip and the processor.
Again the ISP must be connected directly to the processor pins.<br>
<br>
All the best for now,<br>
John <br>
<br>
<br>
At 16:06 12/03/2007, you wrote:<br>
<br>
<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Content-class: urn:content-classes:message<br>
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boundary="----_=_NextPart_001_01C764C0.DFF02675"<br>
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</span></font><font size=2 color=navy><span style='font-size:10.0pt;color:navy'>Thanks
John.<br>
<br>
What is the reason for RXD0 resistor? Haven’t heard about this one
before.<br>
How did you end up with the 1K value?<br>
<br>
</span></font><br>
<font color=navy><span style='color:navy'>Med venlig hilsen / Best regards /
mit freundlichen Grüßen<br>
</span></font><br>
<b><font color=navy><span style='color:navy;font-weight:bold'>EC POWER A/S<br>
</span></font></b><br>
<b><font color=navy><span style='color:navy;font-weight:bold'>Steven Lose<br>
</span></font></b><br>
<font color=navy><span style='color:navy'>Software Ingeniør<br>
</span></font><br>
<font color=navy><span style='color:navy'>Tlf.: +45 87434100<br>
</span></font><br>
<font color=navy><span style='color:navy'>Direkte tlf. +45 58286608<br>
</span></font><br>
<font color=navy><span style='color:navy'>Email: <a
href="blocked::mailto:bsl@ecpower.dk">sl@ecpower.dk</a><br>
</span></font><br>
<font color=navy><span style='color:navy'><a href="http://www.ecpower.dk/"
eudora=autourl>www.ecpower.dk</a> </span></font><o:p></o:p></p>
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