Can I assert multiple CS at a time with NI USB-8452

[csw4004]

Hello,

I am using SPI on NI USB-8452. I would like to control multiple slaves at a time only with MOSI and without MISO connection.

Then, I need to assert multiple CS at a time. Can I do that?

[santo_13]

In that why not tie all those slaves to the same CS?

Anyway, you're going to share the MOSI line for all devices, why not share the CS line too?

As far as I am aware, I don't think you can assert multiple CS synchronously and it does not make sense why?

[csw4004]

Hi Santhosh,

Thanks for your answer. Yes, your idea is right.

However, in my application, in some cases, I need to control the slaves individually.

I would like to decrease the control time by controlling the slaves at a time in the other cases.

It would be very helpful if you let me know the reference describing that I cannot assert multiple CS synchronously.

Thank you.

Sun

[santo_13 · Accepted solution]

I don't have a reference, but from my experience, none of the APIs can do that, hence there is no way to do it - simple as that.

They don't need to explicitly say what cannot be done, instead, you tell what can be done and the rest are not possible.

Alternatively, you can implement external logic gates controlled by a DIO line to toggle them into individual control mode or control by a single CS pin. If you're okay to do SPI scripting, you can use the DIO lines as CS because you can set all DIO states in a single go or even set CS lines one after another and then do the read/write together.