topic LPC800 ISP connect in LPC Microcontrollers https://community.nxp.com/t5/LPC-Microcontrollers/LPC800-ISP-connect/m-p/568938#M17815 <HTML><HEAD></HEAD><BODY><STRONG>Content originally posted in LPCWare by idol on Fri Mar 01 02:30:31 MST 2013</STRONG><BR /><SPAN>when&nbsp; we connect the isp&nbsp; of lpcxpresso LPC812, We must pay attention to R55 that is connected to AD.</SPAN><BR /><SPAN>We must put the resistance welding down,or we cannot connect the isp</SPAN></BODY></HTML> Wed, 15 Jun 2016 20:11:01 GMT lpcware 2016-06-15T20:11:01Z LPC800 ISP connect https://community.nxp.com/t5/LPC-Microcontrollers/LPC800-ISP-connect/m-p/568938#M17815 <HTML><HEAD></HEAD><BODY><STRONG>Content originally posted in LPCWare by idol on Fri Mar 01 02:30:31 MST 2013</STRONG><BR /><SPAN>when&nbsp; we connect the isp&nbsp; of lpcxpresso LPC812, We must pay attention to R55 that is connected to AD.</SPAN><BR /><SPAN>We must put the resistance welding down,or we cannot connect the isp</SPAN></BODY></HTML> Wed, 15 Jun 2016 20:11:01 GMT https://community.nxp.com/t5/LPC-Microcontrollers/LPC800-ISP-connect/m-p/568938#M17815 lpcware 2016-06-15T20:11:01Z Re: LPC800 ISP connect https://community.nxp.com/t5/LPC-Microcontrollers/LPC800-ISP-connect/m-p/568939#M17816 <HTML><HEAD></HEAD><BODY><STRONG>Content originally posted in LPCWare by TheShed on Fri Mar 01 04:45:08 MST 2013</STRONG><BR /><SPAN>Not a great piece of design is it.... </SPAN><BR /><BR /><SPAN>With the trimming pot wound all the way up the external uart can never pull ISP-RX below half rail. In my setup it doesn't get much below 1.9V which is well outside the limit for a valid LOW of 0.3VDD. </SPAN><BR /><SPAN>On the plus side, it is a 22k pot so set it to anywhere *except* against the end stop and it should be fine.</SPAN><BR /><BR /><SPAN>I think this highlights the one flaw I have found so far with the LPC8xx design: The two analogue compare inputs are both assigned to ISP pins. One would have been OK but not both.</SPAN><BR /><BR /><SPAN>Could I request that this is changed for the next part in the family - please...</SPAN><BR /><BR /><SPAN>--</SPAN><BR /><SPAN>mike</SPAN></BODY></HTML> Wed, 15 Jun 2016 20:11:01 GMT https://community.nxp.com/t5/LPC-Microcontrollers/LPC800-ISP-connect/m-p/568939#M17816 lpcware 2016-06-15T20:11:01Z