https://community.nxp.com/t5/LPC-Microcontrollers/LPC178x-UART-38400bps-with-12MHz-IRC/m-p/2075221#M58019 <P>I need to create a RS485/UART communication link between LPC178X and SAMD20 MCU. The communication should be 38400bps.</P><P>The clock on SAMD20 is based on an external 32.768kHz crystal (XOSC32K) and DFLL in closed loop mode.</P><P>I'm wondering if it is possible to clock LPC178X with internal IRC 12MHz oscillator. The datasheet reports a precision of 1% (11.88-12.12MHz) over all the voltages and temperatures. It seems sufficient for UART communication that usually needs a maximum of 2% error.</P> Mon, 07 Apr 2025 14:18:33 GMT giusloq 2025-04-07T14:18:33Z https://community.nxp.com/t5/LPC-Microcontrollers/LPC178x-UART-38400bps-with-12MHz-IRC/m-p/2075221#M58019 <P>I need to create a RS485/UART communication link between LPC178X and SAMD20 MCU. The communication should be 38400bps.</P><P>The clock on SAMD20 is based on an external 32.768kHz crystal (XOSC32K) and DFLL in closed loop mode.</P><P>I'm wondering if it is possible to clock LPC178X with internal IRC 12MHz oscillator. The datasheet reports a precision of 1% (11.88-12.12MHz) over all the voltages and temperatures. It seems sufficient for UART communication that usually needs a maximum of 2% error.</P> Mon, 07 Apr 2025 14:18:33 GMT https://community.nxp.com/t5/LPC-Microcontrollers/LPC178x-UART-38400bps-with-12MHz-IRC/m-p/2075221#M58019 giusloq 2025-04-07T14:18:33Z https://community.nxp.com/t5/LPC-Microcontrollers/LPC178x-UART-38400bps-with-12MHz-IRC/m-p/2076478#M58026 <P>Hello <a href="https://community.nxp.com/t5/user/viewprofilepage/user-id/160419">@giusloq</a>,<BR />I understand that you would use the IRC as core source clock, it is possible, as mentioned in the chapter 1.2 called "Features", as shown in the next image:</P> <P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="Habib_MS_0-1744146716879.png" style="width: 400px;"><img src="https://community.nxp.com/t5/image/serverpage/image-id/332040iE4DC8D20490A97EE/image-size/medium?v=v2&amp;px=400" role="button" title="Habib_MS_0-1744146716879.png" alt="Habib_MS_0-1744146716879.png" /></span></P> <P><BR />Also, if you experience any issue do not hesitate to let me know<BR />BR<BR />Habib.</P> Tue, 08 Apr 2025 21:12:11 GMT https://community.nxp.com/t5/LPC-Microcontrollers/LPC178x-UART-38400bps-with-12MHz-IRC/m-p/2076478#M58026 Habib_MS 2025-04-08T21:12:11Z