MCU-PLUS-SDK-AM263X: MCSPI Sharing

Saman Mardani

Part Number: MCU-PLUS-SDK-AM263X
Other Parts Discussed in Thread: SYSCONFIG

Hi,

I would like to share one MCSPI pins for two or more slaves and select them through CS pin. Would you please let me know how to do it in SysConfig?

Thanks

over 3 years ago

0 Ming Wei over 3 years ago

TI__Guru 55965 points

Hi Saman,

The SysCfg is limited one CS per instance, so it will not work if you are using the SysCfg for sharing one MCSPI instance for multiple SPI slaves.

Here is how you can do accomplish it:

1. Specify a MCSPI instance it 3 pin mode,

2. then connect all SPI slaves into the same SPI bus (three lines, CLK, MISO MOSI),

3. then use the GPIO pins to enable each SPI slave

Bestregards,

Ming

0 Saman Mardani over 3 years ago in reply to Ming Wei

Intellectual 325 points

Hi Ming,

Thanks for the reply.

One more Question: When I define MCSPI in 3 pin mode and de-select CS pin, the CCS fail to build Sysconfig file as you can see in the attachment.

and also, when I want to use C11 pin as a GPIO I get a resource conflict.

Thanks for the help

0 Ming Wei over 3 years ago in reply to Saman Mardani

TI__Guru 55965 points

Hi Samam,

I can add a new MCSPI instance to the Hello World example with 3-pin mode and build it fine. Try to delete the existing MCSPI instance and create a new one from scratch. I am using the latest MCU+ SDK for AM263x 08.04.00.17. Which MCU+ SDK version you are using?

Best regards,

Ming

0 Saman Mardani over 3 years ago in reply to Ming Wei

Intellectual 325 points

Hi Ming,

Can I DE-SELECT "CS" pin after setting to 3-pin mode?

0 Ming Wei over 3 years ago in reply to Saman Mardani

TI__Guru 55965 points

Hi Saman,

Yes, you can uncheck the CS pin, but you have to uncheck the Signal first!

Best regards,

Ming

0 Saman Mardani over 3 years ago in reply to Ming Wei

Intellectual 325 points

Is CS pin de-selected when you build it? since when I de-select CS pin, build fails.

0 Saman Mardani over 3 years ago in reply to Saman Mardani

Intellectual 325 points

I even tested with hello-world example

0 Ming Wei over 3 years ago in reply to Saman Mardani

TI__Guru 55965 points

Hi Samam,

Yes. When I select the 3-pin mode, as you can see the CS check box does not even show up. I re-built the project. There is no build error.

Best regards,

Ming

0 Ming Wei over 3 years ago in reply to Ming Wei

TI__Guru 55965 points

Hi Samam,

What MCU+ SDK version are you using? It is important.

Best regards,

Ming

0 Saman Mardani over 3 years ago in reply to Ming Wei

Intellectual 325 points

Hi Ming,

I was working in MCU+SDK version 8.03 and had problem.

I switched to version 8.04, and it is fixed now. (CS pin disappears when change to 3-Pin mode)

+1 Ming Wei over 3 years ago in reply to Saman Mardani

TI__Guru 55965 points

Hi Samam,

I also checked with the software team. You can actually configure 2 CSs per MCSPI instance, if you choose Multiple Master mode. By default, it is Single Master which only allow one CS per instance.

Best regards,

Ming

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MCU-PLUS-SDK-AM263X: MCSPI Sharing