Dear Okan ERCAN:
For your first question I guess you are ask because of the 4MHz IRC internal generator on the MCG, in this case you cannot use this clock directly as system clock, please see on the clocking diagram, if you want to have a system clock you should configure which Input signal you want for MCGOUTCLK and then configure OUTDIV1 and CG to get the specific system clock frequency you want.
For UART case you will notice that formula to calculate bad rate not only depends of the clock source for UART module, you should also consider OSR (UART0_C4[OSR]) and SBR (UART0_BDH[SBR] and UART0_BDL) values, as is described on the formula:
Baud Rate = Module clock / ((OSR+1) x SBR)
You need to consider all these parameters to verify if you could achieve a specific baud rate, based on the frequencies normally used on this module the common used baud rates (like the ones in the baud rate list on the hyperterminal) could be achieved, please also verify which module clock have you selected.
Regard PCB design I will recommend you the AN4747, EMC Design Tips for Kinetis L Family I hope you could find interesting information here.
Have a nice day,
Perla Moncada
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Note: If this post answers your question, please click the Correct Answer button. Thank you!
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Dear Okan ERCAN:
For your first question I guess you are ask because of the 4MHz IRC internal generator on the MCG, in this case you cannot use this clock directly as system clock, please see on the clocking diagram, if you want to have a system clock you should configure which Input signal you want for MCGOUTCLK and then configure OUTDIV1 and CG to get the specific system clock frequency you want.
For UART case you will notice that formula to calculate bad rate not only depends of the clock source for UART module, you should also consider OSR (UART0_C4[OSR]) and SBR (UART0_BDH[SBR] and UART0_BDL) values, as is described on the formula:
Baud Rate = Module clock / ((OSR+1) x SBR)
You need to consider all these parameters to verify if you could achieve a specific baud rate, based on the frequencies normally used on this module the common used baud rates (like the ones in the baud rate list on the hyperterminal) could be achieved, please also verify which module clock have you selected.
Regard PCB design I will recommend you the AN4747, EMC Design Tips for Kinetis L Family I hope you could find interesting information here.
Have a nice day,
Perla Moncada
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
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