LPC54018 peripheral clock initialization

[Renuga_AKAS]

Hi,

    I tried to configure 48MHz for flexcomm peripheral through clock attach clock function using kFRO_HF_to_FLEXCOMM9. But unable to do so. can yous suggest me how can i convert 98MHz clock frequency to 48MHz.

[ZhangJennie]

Hi Renuga_AKAS 

We use FRO_HF divider to divide FRO96M. please see configuration as below

ZhangJennie_0-1661495506778.png

Hope this helps,

Jun Zhang

[Renuga_AKAS]

Hi,

    Thanks for the reply. I will try to configure the clock as you mentioned above. I have another doubt about clock configuration, is it possible to set clock frequency as below 12MHz?. If yes, it it the same way as mentioned above by dividing the FRO_12M frequency?

[ZhangJennie]

Hi Renuga_AKAS 

According to UM11060, Chapter 8, Fig 21,Fig 22. FRO_HF has FRO clock divider but FRO_12M doesn't have.

ZhangJennie_0-1661767754175.png

So we can't find the same option if using FRO_12M  in clock configuration tool.

Hope this helps

Jun Zhang

[Renuga_AKAS]

Hi,

    Thanks for the useful reply. I still need a clarification is it possible to configure peripheral clock below 12MHz?.

[ZhangJennie · Accepted solution]

Yes. For example, When use FRO_HF, and set FRO_HF divider as 10, we get 9.6M Hz output.

ZhangJennie_0-1661769804509.png

[Renuga_AKAS]

Hi,

    Thanks for the solution.