topic Re: S32K SPI Slave mode in S32K

S32K SPI Slave mode

SunW — Fri, 25 Feb 2022 01:55:37 GMT

Hello

I have two S32K144 EV board.

One board set SPI master. Other board set SPI Slave.

SPI master pin is

SPI0_CLK(PB2)

SPI0_MISO(PB3)

SPI0_MOSI(PB4)

SPI0_CS(PB0)

SLAVE

SPI1_CLK(PD0)

SPI1_MISO(PD2)

SPI1_MOSI(PD1)

SPI1_CS(PD3)

In case master, I set Chip select pin Software GPIO

In case slave, I set chip Hardware cs.

but I can't understand SPI slave cs timing.

If Master ChipSelect pin is low, slave SPI chipSelect set low.

How do i check SPI slave chipselect low?

Master sudo code

- cs low

- SPI_transmit

- SPI receive

- cs high

slave Sudo code

- get cs pin low (how do i check pin low?)

- SPI_receive data

- SPI_transmit

- get cd pin high

Re: S32K SPI Slave mode

Senlent — Fri, 25 Feb 2022 06:31:40 GMT

Hi@sunW

you said :If Master ChipSelect pin is low, slave SPI chipSelect set low.

this is not right. the slave cs pin direction should be set to Input, and the voltage level of the CS signal which depends on Master 's CS control only.

take a look at the example project:lpspi_transfer_s32k14x, it will show the LPSPI Master and Slave functionalities.

BR!

Jim,

Re: S32K SPI Slave mode

SunW — Fri, 25 Feb 2022 12:42:50 GMT

I already saw this project.

Buy i can't find method

When do i get slave data in MISO.

I try to set cs pin as port interrupt.

So Spi communicaion is not working.

Re: S32K SPI Slave mode

Senlent — Mon, 28 Feb 2022 08:24:58 GMT

Hi@SunW

I understand what you mean, you want to enable send &receive by reading the status of CS pin, but the CS pin is not a GPIO port in this example project, so you can't do it through IO interrupt( i guess this is the reason why the SPI communication is not working. )

This answer is very similar to your question, you can refer to this answer.

https://community.nxp.com/t5/S32-SDK/How-do-I-know-if-the-SPI-slave-has-received-the-data/m-p/849975

BR!

Jim,