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    <title>topic WDT clarifications in LPCXpresso IDE</title>
    <link>https://community.nxp.com/t5/LPCXpresso-IDE/WDT-clarifications/m-p/593930#M30692</link>
    <description>&lt;HTML&gt;&lt;HEAD&gt;&lt;/HEAD&gt;&lt;BODY&gt;&lt;STRONG&gt;Content originally posted in LPCWare by Genesy on Wed Oct 16 03:45:22 MST 2013&lt;/STRONG&gt;&lt;BR /&gt;&lt;SPAN&gt;Hi, &lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;I looked the old example of WDT for LPC11xx (not the new LPCOpen driver).&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;I read in the manual that the WDT has a frequency clock of 8Khz with a fixed prescaler of 4.&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;Then, if I'm not mistaken, the WDT timer step is of:&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;1/8000 * 4 = 0,0005 s = 500us&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;though the minimun counter value is of 256(0xff) &lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;then the minimum interval is of 0,0005 * 256 = 0,128ms.&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;In the driver that I looked there isn't a way to set the counter value, but it is initialized by the WDTInit() function,&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;that haven't parameter, at the default value of 1023(0x3FF).&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;For this value, then the interval is of 0,0005*1023 = 0,5115 s = 511,5 ms is right?&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;In the driver_config.h file there is also a defined macro WDT_FEED_VALUEthat is set at (8000*1), &lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;but it doesn't seem to used in the program.&amp;nbsp; What is this macro?&lt;/SPAN&gt;&lt;BR /&gt;&lt;BR /&gt;&lt;SPAN&gt;Thank you very much&lt;/SPAN&gt;&lt;BR /&gt;&lt;/BODY&gt;&lt;/HTML&gt;</description>
    <pubDate>Wed, 15 Jun 2016 21:31:30 GMT</pubDate>
    <dc:creator>lpcware</dc:creator>
    <dc:date>2016-06-15T21:31:30Z</dc:date>
    <item>
      <title>WDT clarifications</title>
      <link>https://community.nxp.com/t5/LPCXpresso-IDE/WDT-clarifications/m-p/593930#M30692</link>
      <description>&lt;HTML&gt;&lt;HEAD&gt;&lt;/HEAD&gt;&lt;BODY&gt;&lt;STRONG&gt;Content originally posted in LPCWare by Genesy on Wed Oct 16 03:45:22 MST 2013&lt;/STRONG&gt;&lt;BR /&gt;&lt;SPAN&gt;Hi, &lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;I looked the old example of WDT for LPC11xx (not the new LPCOpen driver).&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;I read in the manual that the WDT has a frequency clock of 8Khz with a fixed prescaler of 4.&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;Then, if I'm not mistaken, the WDT timer step is of:&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;1/8000 * 4 = 0,0005 s = 500us&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;though the minimun counter value is of 256(0xff) &lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;then the minimum interval is of 0,0005 * 256 = 0,128ms.&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;In the driver that I looked there isn't a way to set the counter value, but it is initialized by the WDTInit() function,&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;that haven't parameter, at the default value of 1023(0x3FF).&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;For this value, then the interval is of 0,0005*1023 = 0,5115 s = 511,5 ms is right?&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;In the driver_config.h file there is also a defined macro WDT_FEED_VALUEthat is set at (8000*1), &lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;but it doesn't seem to used in the program.&amp;nbsp; What is this macro?&lt;/SPAN&gt;&lt;BR /&gt;&lt;BR /&gt;&lt;SPAN&gt;Thank you very much&lt;/SPAN&gt;&lt;BR /&gt;&lt;/BODY&gt;&lt;/HTML&gt;</description>
      <pubDate>Wed, 15 Jun 2016 21:31:30 GMT</pubDate>
      <guid>https://community.nxp.com/t5/LPCXpresso-IDE/WDT-clarifications/m-p/593930#M30692</guid>
      <dc:creator>lpcware</dc:creator>
      <dc:date>2016-06-15T21:31:30Z</dc:date>
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