To: rsgb_lf_group@yahoogroups.co.uk, rsgb_lf_group@blacksheep.org
References: <CAA8k23Qu9=9LgBr+FzqB55LKjSiiKimZBHJ1=gwfi70cYDdcrw@mail.gmail.com>
From: =?UTF-8?Q?Wolfgang_B=c3=bcscher?= <dl4yhf@freenet.de>
Message-ID: <5706C7DD.4030800@freenet.de>
Date: Thu, 7 Apr 2016 22:49:33 +0200
User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:38.0) Gecko/20100101
 Thunderbird/38.7.1
MIME-Version: 1.0
In-Reply-To: <CAA8k23Qu9=9LgBr+FzqB55LKjSiiKimZBHJ1=gwfi70cYDdcrw@mail.gmail.com>
Subject: LF: Re: [rsgb_lf_group] Fast Serial Interfacing with PICs
Content-Type: multipart/alternative;
 boundary="------------010106010400080707050006"
Sender: owner-rsgb_lf_group@blacksheep.org
Precedence: bulk
Reply-To: rsgb_lf_group@blacksheep.org
Status: O

This is a multi-part message in MIME format.
--------------010106010400080707050006
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit

Hi Andy,

It was me, using a PIC16F1783 with 1 MBaud on an FTDI-based interface.
At higher bitrates, there were occasionally lost samples depending on 
the CPU load of the PC. So it wasn't a problem with the PIC, and not a 
problem with the hardware, but most likely a problem with the USB driver.

All the best,
    Wolf DL4YHF .

Am 07.04.2016 um 12:09 schrieb Andy Talbot andy.g4jnt@gmail.com 
[rsgb_lf_group]:
>
>
> I know the subject is nothing to do with LF, but I didn't keep the 
> original thread...
>
> A few months ago someone on one of these two LF reflectors pointed me 
> at the Enhanced USART in the 16F688 and later PIC devices, saying how 
> the baud rate could be set as high as Fosc / 4. So getting 3M Baud 
> with a 12MHz Xtal for compatibility with FTDI chip COM ports at thier 
> highest setting.
>
> Who was it and have you managed to do this?   I finally got round to 
> testing a 16F688 at 3Meg   and am getting some funny results that mean 
> sometimes the PIC's EUSART sends the right data, and sometimes it gets 
> itself tied up in knots, sending one character several times
>
> It is not a programming error either, as the code works perfectly at 
> lower baud rates, by just changing the divider. The nature of the 
> problem looks and feels like something inherent to the internals of 
> the chip
>
> Andy  G4JNT
>
>
>
> __._,_.___
> ------------------------------------------------------------------------
> Posted by: Andy Talbot <andy.g4jnt@gmail.com>
> ------------------------------------------------------------------------
>
>
> Visit Your Group 
> <https://uk.groups.yahoo.com/neo/groups/rsgb_lf_group/info;_ylc=X3oDMTJmNnF1bDd2BF9TAzk3NDkwNTA1BGdycElkAzg1MDgwODk1BGdycHNwSWQDMTY5MDA2MzEwOARzZWMDdnRsBHNsawN2Z2hwBHN0aW1lAzE0NjAwMjM3ODc-> 
>
>
>   * New Members
>     <https://uk.groups.yahoo.com/neo/groups/rsgb_lf_group/members/all;_ylc=X3oDMTJnOXE0OXRnBF9TAzk3NDkwNTA1BGdycElkAzg1MDgwODk1BGdycHNwSWQDMTY5MDA2MzEwOARzZWMDdnRsBHNsawN2bWJycwRzdGltZQMxNDYwMDIzNzg3>
>     1
>
> Yahoo! Groups 
> <https://uk.groups.yahoo.com/neo;_ylc=X3oDMTJlM2pmN3ZrBF9TAzk3NDkwNTAzBGdycElkAzg1MDgwODk1BGdycHNwSWQDMTY5MDA2MzEwOARzZWMDZnRyBHNsawNnZnAEc3RpbWUDMTQ2MDAyMzc4Nw--> 
>
> • Privacy 
> <https://info.yahoo.com/privacy/uk/yahoo/groups/details.html> • 
> Unsubscribe 
> <mailto:rsgb_lf_group-unsubscribe@yahoogroups.co.uk?subject=Unsubscribe> 
> • Terms of Use 
> <https://info.yahoo.com/legal/uk/yahoo/utos/en-gb/details.html>
>
> __,_._,___


--------------010106010400080707050006
Content-Type: text/html; charset=utf-8
Content-Transfer-Encoding: 8bit

<html>
  <head>
    <meta content="text/html; charset=utf-8" http-equiv="Content-Type">
  </head>
  <body text="#000000" bgcolor="#FFFFFF">
    Hi Andy,<br>
    <br>
    It was me, using a PIC16F1783 with 1 MBaud on an FTDI-based
    interface.<br>
    At higher bitrates, there were occasionally lost samples depending
    on the CPU load of the PC. So it wasn't a problem with the PIC, and
    not a problem with the hardware, but most likely a problem with the
    USB driver.<br>
    <br>
    All the best,<br>
       Wolf DL4YHF .<br>
    <br>
    <div class="moz-cite-prefix">Am 07.04.2016 um 12:09 schrieb Andy
      Talbot <a class="moz-txt-link-abbreviated" href="mailto:andy.g4jnt@gmail.com">andy.g4jnt@gmail.com</a> [rsgb_lf_group]:<br>
    </div>
    <blockquote
cite="mid:CAA8k23Qu9=9LgBr+FzqB55LKjSiiKimZBHJ1=gwfi70cYDdcrw@mail.gmail.com"
      type="cite">
      <style type="text/css">
<!--

/* start of attachment style */
       .ygrp-photo-title{
         clear: both;
         font-size: smaller;
         height: 15px;
         overflow: hidden;
         text-align: center;
         width: 75px;
       }
       div.ygrp-photo{
         background-position: center;
         background-repeat: no-repeat;
         background-color: white;
         border: 1px solid black;
         height: 62px;
         width: 62px;
       }

       div.photo-title 
         a,
         div.photo-title a:active,
         div.photo-title a:hover,
         div.photo-title a:visited {
           text-decoration: none; 
       }

       div.attach-table div.attach-row {
         clear: both;
       }

       div.attach-table div.attach-row div {
         float: left;
         /* margin: 2px;*/
       }

       p {
         clear: both;
         padding: 15px 0 3px 0;
	 overflow: hidden;
       }

       div.ygrp-file {
         width: 30px;
         valign: middle;
       }
       div.attach-table div.attach-row div div a {
         text-decoration: none;
       }

       div.attach-table div.attach-row div div span {
         font-weight: normal;
       }

       div.ygrp-file-title {
         font-weight: bold;
       }
 /* end of attachment style */
        -->
        </style>
      <style type="text/css">
<!--
#ygrp-mkp {
  border: 1px solid #d8d8d8;
  font-family: Arial;
  margin: 10px 0;
  padding: 0 10px;
}

#ygrp-mkp hr {
  border: 1px solid #d8d8d8;
}

#ygrp-mkp #hd {
  color: #628c2a;
  font-size: 85%;
  font-weight: 700;
  line-height: 122%;
  margin: 10px 0;
}

#ygrp-mkp #ads {
  margin-bottom: 10px;
}

#ygrp-mkp .ad {
  padding: 0 0;
}

#ygrp-mkp .ad p {
  margin: 0;
}

#ygrp-mkp .ad a {
  color: #0000ff;
  text-decoration: none;
}
-->
</style><!-- |**|begin egp html banner|**| -->
      <br>
      <br>
      <!-- |**|end egp html banner|**| -->
      <div dir="ltr">I know the subject is nothing to do with LF, but I
        didn't keep the original thread...
        <div><br>
        </div>
        <div>A few months ago someone on one of these two LF reflectors
          pointed me at the Enhanced USART in the 16F688 and later PIC
          devices, saying how the baud rate could be set as high as Fosc
          / 4. So getting 3M Baud with a 12MHz Xtal for compatibility
          with FTDI chip COM ports at thier highest setting.</div>
        <div><br>
        </div>
        <div>Who was it and have you managed to do this?   I finally got
          round to testing a 16F688 at 3Meg   and am getting some funny
          results that mean sometimes the PIC's EUSART sends the right
          data, and sometimes it gets itself tied up in knots, sending
          one character several times</div>
        <div><br>
        </div>
        <div>It is not a programming error either, as the code works
          perfectly at lower baud rates, by just changing the divider.  
          The nature of the problem looks and feels like something
          inherent to the internals of the chip </div>
        <div><br>
        </div>
        <div>Andy  G4JNT</div>
        <div><br>
        </div>
      </div>
      <!-- |**|begin egp html banner|**| -->
      <br>
      <br>
      <!-- |**|end egp html banner|**| -->
      <div width="1" style="color: white; clear: both;">__._,_.___</div>
      <div id="fromDMARC" style="clear:both; margin-top: 10px;">
        <hr style="height:2px ; border-width:0; color:#E3E3E3;
          background-color:#E3E3E3;"> Posted by: Andy Talbot
        <a class="moz-txt-link-rfc2396E" href="mailto:andy.g4jnt@gmail.com">&lt;andy.g4jnt@gmail.com&gt;</a>
        <hr style="height:2px ; border-width:0; color:#E3E3E3;
          background-color:#E3E3E3;"> </div>
      <!-- Start Recommendations -->
      <!-- End Recommendations -->
      <!-- |**|begin egp html banner|**| --> <img
        moz-do-not-send="true"
src="http://geo.yahoo.com/serv?s=97490503/grpId=85080895/grpspId=1690063108/msgId=5989/stime=1460023787"
        height="1" width="1"> <br>
      <!-- |**|end egp html banner|**| -->
      <!-- |**|begin egp html banner|**| -->
      <br>
      <!-- |**|begin egp html banner|**| -->
      <div id="ygrp-vital" style="background-color: #f2f2f2;
        font-family: Verdana; font-size: 10px; margin-bottom: 10px;
        padding: 10px;"> <span id="vithd" style="font-weight: bold;
          color: #333; text-transform: uppercase; "><a
            moz-do-not-send="true"
href="https://uk.groups.yahoo.com/neo/groups/rsgb_lf_group/info;_ylc=X3oDMTJmNnF1bDd2BF9TAzk3NDkwNTA1BGdycElkAzg1MDgwODk1BGdycHNwSWQDMTY5MDA2MzEwOARzZWMDdnRsBHNsawN2Z2hwBHN0aW1lAzE0NjAwMjM3ODc-"
            style="text-decoration: none;">Visit Your Group</a></span>
        <ul style="list-style-type: none; margin: 0; padding: 0;
          display: inline;">
          <li style="border-right: 1px solid #000; font-weight: 700;
            display: inline; padding: 0 5px; margin-left: 0;"> <span
              class="cat"><a moz-do-not-send="true"
href="https://uk.groups.yahoo.com/neo/groups/rsgb_lf_group/members/all;_ylc=X3oDMTJnOXE0OXRnBF9TAzk3NDkwNTA1BGdycElkAzg1MDgwODk1BGdycHNwSWQDMTY5MDA2MzEwOARzZWMDdnRsBHNsawN2bWJycwRzdGltZQMxNDYwMDIzNzg3"
                style="text-decoration: none;">New Members</a></span> <span
              class="ct" style="color: #ff7900;">1</span> </li>
        </ul>
      </div>
      <div id="ft" style="font-family: Arial; font-size: 11px;
        margin-top: 5px; padding: 0 2px 0 0; clear: both;"> <a
          moz-do-not-send="true"
href="https://uk.groups.yahoo.com/neo;_ylc=X3oDMTJlM2pmN3ZrBF9TAzk3NDkwNTAzBGdycElkAzg1MDgwODk1BGdycHNwSWQDMTY5MDA2MzEwOARzZWMDZnRyBHNsawNnZnAEc3RpbWUDMTQ2MDAyMzc4Nw--"
          style="float: left;"><img moz-do-not-send="true"
src="http://l.yimg.com/ru/static/images/yg/img/email/new_logo/yahoo_groups_en-GB_137x19.png"
            alt="Yahoo! Groups" style="border: 0;" height="19"
            width="137"></a>
        <div style="color: #747575; float: right;"> • <a
            moz-do-not-send="true"
            href="https://info.yahoo.com/privacy/uk/yahoo/groups/details.html"
            style="text-decoration: none;">Privacy</a> • <a
            moz-do-not-send="true"
href="mailto:rsgb_lf_group-unsubscribe@yahoogroups.co.uk?subject=Unsubscribe"
            style="text-decoration: none;">Unsubscribe</a> • <a
            moz-do-not-send="true"
            href="https://info.yahoo.com/legal/uk/yahoo/utos/en-gb/details.html"
            style="text-decoration: none;">Terms of Use</a> </div>
      </div>
      <!-- |**|end egp html banner|**| -->
      <!-- ygrp-msg --> <br>
      <!-- |**|end egp html banner|**| -->
      <div style="color: white; clear: both;">__,_._,___</div>
    </blockquote>
    <br>
  </body>
</html>

--------------010106010400080707050006--