Peripheral Chip Select on K22

[gibson486]

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

[kerryzhou]

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

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

[mjbcswitzerland]

Hi

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