Kinetis MicrocontrollersのトピックHow to setup KEA128 SPI0 at PTE0~3?

How to setup KEA128 SPI0 at PTE0~3?

younghwanbae — Fri, 29 May 2015 23:21:37 GMT

I added below code for changing pin to PTE0~3,

SIM_PINSEL0 |= SIM_PINSEL_SPI0PS_MASK;

// set PTE0~3 as SPI0

I'm using below functions.

void SPI_Write(SPI_MemMapPtr base, uint8 u8Write)

{

while (!SPISR_SPTEF(base)); /* sending finish? */

SPI_D_REG(base) = u8Write;

}

uint8 SPI_Read(SPI_MemMapPtr base)

{

while(!SPISR_SPRF(base)); /* read finish? */

return SPI_D_REG(base);

}

I tested simple code like below,

CS0_LOW();

SPI_Write(); // 1 byte write

SPI_Read(); // 1 byte read

CS0_HIGH();

But, problem is write function looks like normal, but read function doesn't work.

when CS goes LOW, only 8 clocks out.

Looks like "SPISR_SPRF(base)", is already set.

How can I solve this problem?

Re: How to setup KEA128 SPI0 at PTE0~3?

derek_lau — Sat, 30 May 2015 17:01:03 GMT

SPI is a bi-directional communication with write and read at the same time.

What you need is:

SPI_WRITE

SPI_DUMMY_READ // clear SPRF

SPI_DUMY_WRITE // write any data

SPI_READ

Re: How to setup KEA128 SPI0 at PTE0~3?

younghwanbae — Mon, 01 Jun 2015 18:21:45 GMT

Actually I connected SPI0 port with SPI_Flash memory.

It's time should be like below.

CS ---_______________________________________----

MOSI ---<cmd><data><data><data>-----------------------------

MISO --- ----------------------------------<data><data><data>---

But, KEA128' output is

SS ---_____--____--____--____--_____--____--____----

In this case I cannot use SS pin as CS, can I?

I should program SPI slave mode also work like above.

How can I make slave mode of KEA128's SPI like this?

Regards,

Younghwan

Re: How to setup KEA128 SPI0 at PTE0~3?

Hui_Ma — Tue, 02 Jun 2015 05:33:29 GMT

Hi,

When you want to use KEA128 PTE0~3 pins as SPI0 module related pin, it need to set SIM_PINSEL0[SPI0PS] bit.

After that, for you want to use KEA128 SPI0 as master to read data from external SPI Flash, it need to enable SPI0_C1[MSTR] bit to set SPI0 module works as master.

Wish it helps.

Have a great day,
Ma Hui

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