AM3359: How to control 7 SPI devies with SPI0?

user5358500

Part Number: AM3359
Other Parts Discussed in Thread: SN74CB3Q3251

Hi Ti

We have an issue about SPI design, We know AM3359 have 2xSPI, but we have 7xSPI decide

Our Plan as follows:

1.Share SPI0_MISO/SPI0_MOSI/SPI0_CLK with 7x Devices

2.Connect SPI0_CS0 of AM3359 with MULTIPLEXERs（Eg. SN74CB3Q3251 1 of 8），and connect other GPIOs(4x) with MULTIPLEXER

then we can control all 7xspi devices with a MULTIPLEXER(000 to 111)

Does it work?

Do you have another solution?

Thanks

+1 Nick Saulnier over 4 years ago

Hello,

You have several options.

One option is to connect up to 4 SPI external slave devices to each McSPI instance. See thread "Linux Device tree, only first 4 SPI1 childs works." for more details:
(+) AM3357: Linux Device tree, only first 4 SPI1 childs works. - Processors forum - Processors - TI E2E support forums

If you are comfortable with PRU firmware development, you could also use the PRU-ICSS in AM335x to interface with multiple SPI instances. See TI Design "Flexible Interface (PRU-ICSS) Reference Design for Simultaneous, Coherent DAQ Using Multiple ADCs": TIDA-01555 Flexible Interface (PRU-ICSS) Reference Design for Simultaneous, Coherent DAQ Using Multiple ADCs | TI.com

The SPI topology you mentioned might be possible, but I am not sure whether there is a software framework to support it.

Regards,

Nick