topic What is the sample point for? in LPC FAQs https://community.nxp.com/t5/LPC-FAQs/What-is-the-sample-point-for/m-p/590701#M154 <HTML><HEAD></HEAD><BODY><P>The sample point is the location, typically given as a percent value, inside each bit period where the CAN controller looks at the state of the bus and determines if it is a logic zero (dominant) or logic one (recessive). All CAN controllers allow this point to be configured and it is always specified as a percentage from the start of the bit period.<BR />The location of the sample point is a trade-off. An early sample point decreases the sensitivity to oscillator tolerances and allows lower-quality oscillators. A late sample point allows for a longer signal propagation time and therefore a longer bus. A later sample point is useful for non-ideal bus topologies.<BR />The CAN-in-Automation user’s group makes recommendations of where the sample point should be for various bit rates, with 87.5% the most common.</P><P></P><P></P><P><SPAN style="font-size: 11.0pt;">"FAQ contribution from Embedded Systems Academy, experts in CAN bus. For more information visit <A href="http://www.esacademy.com">www.esacademy.com</A>"</SPAN></P></BODY></HTML> Fri, 02 Sep 2016 21:56:55 GMT lpcware 2016-09-02T21:56:55Z What is the sample point for? https://community.nxp.com/t5/LPC-FAQs/What-is-the-sample-point-for/m-p/590701#M154 <HTML><HEAD></HEAD><BODY><P>The sample point is the location, typically given as a percent value, inside each bit period where the CAN controller looks at the state of the bus and determines if it is a logic zero (dominant) or logic one (recessive). All CAN controllers allow this point to be configured and it is always specified as a percentage from the start of the bit period.<BR />The location of the sample point is a trade-off. An early sample point decreases the sensitivity to oscillator tolerances and allows lower-quality oscillators. A late sample point allows for a longer signal propagation time and therefore a longer bus. A later sample point is useful for non-ideal bus topologies.<BR />The CAN-in-Automation user’s group makes recommendations of where the sample point should be for various bit rates, with 87.5% the most common.</P><P></P><P></P><P><SPAN style="font-size: 11.0pt;">"FAQ contribution from Embedded Systems Academy, experts in CAN bus. For more information visit <A href="http://www.esacademy.com">www.esacademy.com</A>"</SPAN></P></BODY></HTML> Fri, 02 Sep 2016 21:56:55 GMT https://community.nxp.com/t5/LPC-FAQs/What-is-the-sample-point-for/m-p/590701#M154 lpcware 2016-09-02T21:56:55Z