topic Peripheral Chip Select on K22 in Kinetis Microcontrollers

Peripheral Chip Select on K22

gibson486 — Wed, 30 Dec 2015 02:35:42 GMT

How are the Peripheral Chip Select pins different than just taking a normal digital out and using that as a chip select?

Re: Peripheral Chip Select on K22

mjbcswitzerland — Wed, 30 Dec 2015 05:24:56 GMT

The K22 has two different SPI interfaces, one with 1 deep FIFO and 1 with 4 byte deep FIFO.

When using the 4 deep FIFO it is possible to program the behaviour of the CS for each byte prepared - in case of the single depth FIFO this is not an option so the advantage is not the same on all SPI instances - one needs to be careful since the driver of each may need to be different!

When using CS peripheral lines it is also possible to specifiy some timing behavior so that there is a certain delay before or after data.

In most cases it is however just as easy (and sometimes easier) to control them with a port output instead.

Regards

Mark

Re: Peripheral Chip Select on K22

kerryzhou — Wed, 30 Dec 2015 06:35:07 GMT

Hi Andrew Chin,

Do you mean you want to use the GPIO in K22 as the peripheral chip select pins? Or the module's pin in the K22, if it is the module's pin, which module you are using?

If you just use the GPIO, you need check the IO current driver ability, whether it is enough to driver your peripheral chip, more details, please refer to the K22 datasheet.

Wish it helps you!

If you still have question, please contact me!

Have a great day,

Jingjing

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