topic Re: LPC4330 UARTbaudrate in LPC Microcontrollers https://community.nxp.com/t5/LPC-Microcontrollers/LPC4330-UARTbaudrate/m-p/656404#M26079 <HTML><HEAD></HEAD><BODY><P>The equation is correct as is (and wrong with your change). DLM and DLL are 8 bit quantities, so to get the 16 bit</P><P>divisor: 256 * (most significant byte) + (least significant byte) [Computer Science 101 Duh]</P><P>The factor of 16 is built in to the equation (the 16 in the divisor part) so go for 9600, 19200 etc. as one might expect.</P><P></P><P>Cheers, Mike.</P></BODY></HTML> Tue, 27 Sep 2016 22:05:06 GMT mikesimmonds 2016-09-27T22:05:06Z LPC4330 UARTbaudrate https://community.nxp.com/t5/LPC-Microcontrollers/LPC4330-UARTbaudrate/m-p/656403#M26078 <HTML><HEAD></HEAD><BODY><P style="margin: 0in 0in 0pt;"><SPAN style="color: #000000; font-family: Calibri; font-size: medium;">Page 1134 of the User Manual gives the equation for the UARTbaudrate. Section 40.6.3 on page 1123 of the User Manual states that :”… the baud rate clock, which must be 16x the desired baud rate”. Does this mean that the UARTbaudrate equation on page 1134 must generate a baud rate that is 16x the desired baud rate?</SPAN></P><P></P><P style="margin: 0in 0in 0pt;"></P><P style="margin: 0in 0in 0pt;"><SPAN style="color: #000000; font-family: Calibri; font-size: medium;">The following UARTbaudrate equation is copied from page 1134 of the User Manual:</SPAN></P><P style="margin: 0in 0in 0pt;"><SPAN style="color: #000000; font-family: Calibri; font-size: medium;">&nbsp;</SPAN><SPAN style="color: #000000; font-family: Calibri; font-size: medium;">UARTbaudrate = PCLK / (16*(256*DLM+DLL)*(1+DivAddVal/MulVal)).</SPAN></P><P style="margin: 0in 0in 0pt;"><SPAN style="color: #000000; font-family: Calibri; font-size: medium;">&nbsp;</SPAN></P><P style="margin: 0in 0in 0pt;"><SPAN style="color: #000000; font-family: Calibri; font-size: medium;">Is the above equation correct or should the equation be (note added parentheses around (DLM + DLL)):</SPAN></P><P style="margin: 0in 0in 0pt;"><SPAN style="color: #000000; font-family: Calibri; font-size: medium;">&nbsp;</SPAN><SPAN style="color: #000000; font-family: Calibri; font-size: medium;">UARTbaudrate = PCLK / (16*(256*(DLM+DLL))*(1+DivAddVal/MulVal))?</SPAN></P></BODY></HTML> Tue, 27 Sep 2016 10:51:57 GMT https://community.nxp.com/t5/LPC-Microcontrollers/LPC4330-UARTbaudrate/m-p/656403#M26078 tomsaluzzo 2016-09-27T10:51:57Z Re: LPC4330 UARTbaudrate https://community.nxp.com/t5/LPC-Microcontrollers/LPC4330-UARTbaudrate/m-p/656404#M26079 <HTML><HEAD></HEAD><BODY><P>The equation is correct as is (and wrong with your change). DLM and DLL are 8 bit quantities, so to get the 16 bit</P><P>divisor: 256 * (most significant byte) + (least significant byte) [Computer Science 101 Duh]</P><P>The factor of 16 is built in to the equation (the 16 in the divisor part) so go for 9600, 19200 etc. as one might expect.</P><P></P><P>Cheers, Mike.</P></BODY></HTML> Tue, 27 Sep 2016 22:05:06 GMT https://community.nxp.com/t5/LPC-Microcontrollers/LPC4330-UARTbaudrate/m-p/656404#M26079 mikesimmonds 2016-09-27T22:05:06Z