CodeWarrior Development Tools中的主题 Re: How to control a SPI(SynchroMaster) CS pin directly?

How to control a SPI(SynchroMaster) CS pin directly?

修華許 — Sun, 28 Jun 2015 16:11:33 GMT

I am using a FRDM-KE06Z board.

I use PE to establish a SynchroMaster in my project.

It seems that freescale's SPI function like SendChar and RecvChar has already control CS pin of SPI automatically

( In other MCU, I have control CS pin directly)

My problem is that Sometimes I need to control the CS pin of SPI interface directly to wake up the external IC

Can I assign the CS pin in PE as BitIO in the same time?

Thanks for help

Re: How to control a SPI(SynchroMaster) CS pin directly?

BlackNight — Sun, 28 Jun 2015 18:22:25 GMT

Yes, in all my applications I have the CS pin disabled in the SynchroMaster component, and use a normal BitIO instead.

Erich

Re: How to control a SPI(SynchroMaster) CS pin directly?

修華許 — Sun, 28 Jun 2015 18:47:25 GMT

But I try to Disable the Slave select pin.

The value is fixed at enable and can't be changed .

How can you disable the Slave pin?

Do you use another pin instead and ignore the default CS pin ?

I use FRDM-KE06Z board.

Re: How to control a SPI(SynchroMaster) CS pin directly?

BlackNight — Sun, 28 Jun 2015 18:59:28 GMT

Hmm, maybe disabling the CS pin is not supported by the hardware? Otherwise this would be a bug of Processor Expert in my view.

You should be able to use a BitIO in parallel, but then at least you need to enable Pin Sharing.

See "Pin with Pin Sharing" in Tutorial: Bits and Pins with Kinetis and the FRDM-KL25Z Board | MCU on Eclipse

I hope this helps,

Erich

Re: How to control a SPI(SynchroMaster) CS pin directly?

修華許 — Sun, 28 Jun 2015 21:46:53 GMT

Thanks.

I try to follow your article to set pin sharing

And find that pin sharing option is not allowed to set.

Bad News.

Re: How to control a SPI(SynchroMaster) CS pin directly?

mstroven — Mon, 02 Nov 2015 23:37:18 GMT

Hi Erich,

The hardware supports it. It looks like another PEx bug. If you instantiate an "SPI_Init" Hardware Initialization component, you can chose to use the Slave Select pin, or not. However if you want the full-featured SPI high-level component, you don't get the choice.