Kinetis Microcontrollers中的主题 Re: Maximum SPI Communication Speed for KM34 at 75 MHz CPU Frequency

Maximum SPI Communication Speed for KM34 at 75 MHz CPU Frequency

Gohil — Thu, 06 Feb 2025 10:01:37 GMT

Hello NXP Community,

I am currently working with the KM34 microcontroller and running it at a 75 MHz CPU frequency. Could someone please clarify what the maximum SPI communication speed is for this configuration?

Additionally, are there any specific considerations or limitations when configuring SPI on this microcontroller at the 75 MHz CPU frequency? Any recommendations to achieve the highest SPI performance would be greatly appreciated!

Thank you for your support!

Re: Maximum SPI Communication Speed for KM34 at 75 MHz CPU Frequency

ZhangJennie — Fri, 07 Feb 2025 14:02:52 GMT

Hi Gohil ,

According to KM34 DS

https://www.nxp.com.cn/docs/en/data-sheet/KM34P144M75SF0.pdf

maximum frequency of SPI operation is half of the system clock in master mode. If you have 75 MHz CPU Frequency, this value is 75/2=37.5 MHz.

maximum frequency of SPI operation is one-fourth of the system clock in slave mode. If the CPU Frequency is 75 MHz , this value is 75/4= 18.75 MHz.

For more about the SPI specification, see above DS, section 3.6.3 SPI switching specifications.

Hope this helps,

Jun Zhang