MCXN236/x4x SPI max speed when connet more than one slave SPI device.

[seanwu]

Dear sir,

Now I want to use MCXN236 Flexcomm to be SPI feature, and use CS[n] to connect to 1~4 slave SPI devices. I want to know the max speed when connect more than one slave SPI devices. What the max speed is, when using one CS to connect one slave SPI device ,and what the max speed is, when using two CS to connect two slave SPI device...

Thanks.

BR,

Sean Wu.

Weikeng

[seanwu]

Dear  @Harry_Zhang,

You mean that if I use LPSPI6 in OD mode to connect two slave SPI devices with two CSs, then the two devices speed are still 75MHz, right? 

Thanks. BR,

Sean Wu.

[Harry_Zhang]

Hi @seanwu 

Yes, because even if two devices are connected, only one device is working at the same time. They can all work at maximum speed.

Hope this will help you.

BR

Hang

[Harry_Zhang]

Hi @seanwu 

According to MCXN23x data sheet

4.6.2 LPSPI switching specifications.

Frequency of operation

In OD mode  

LPSPI0–LPSPI2     25MHz

LPSPI3–LPSPI5     50MHz

LPSPI6–LPSPI7     75MHz

In SD mode

LPSPI0–LPSPI2     21MHz

LPSPI3–LPSPI5     32MHz

LPSPI6–LPSPI7     50MHz

In MD mode

LPSPI0–LPSPI2     12.5MHz

LPSPI3–LPSPI5     25MHz

LPSPI6–LPSPI7     25MHz

Then theoretically, both slave devices also support the same high speed,  the speed could remain the same as when connecting one device.

Hope this will help you.

BR

Hang