8 Replies Latest reply on Sep 26, 2019 12:56 PM by GlFi_4375836

    PSoC 4 UART not working if clock IMO trimmed with WCO


      I am using the CY8C4247AZI-M485 on a CAN bus project. To use the internal clock to drive a CAN bus the WCO must be enabled and used to trim IMO. However when I trim IMO with WCO I cannot get a serial port UART to work. I simplified my project to just have one UART to talk to a terminal. Everything works fine as long as "Trim" on IMO is set to none. If I set the trim with WCO the UART no longer works. I have tried several baud rates and using the UART with and without "clock from terminal" selected. I make sure that the actual baud rate of the component is within less than 2.5% of the baud rate of the display terminal. In all settings just switching trim from "WCO" to "none" allows the UART to write to the terminal. This wouldn't be a problem except that the next step of the project requires the addition of a CAN bus component which will require WCO trim. Thoughts? Things to try?