[National Technology N32G457 Review] RT_Thread Studio SPI Filling the Pit

lugl4313820

[National Technology N32G457 Review] RT_Thread Studio SPI Filling the Pit [Copy link]

 

The problem of NSS not being able to be lowered was solved this morning:

Check the configuration function of drv_spi.c:

Combined with the debugging data:

Found that CLKPOL is 2, and the parameters I passed in are:

cfg.mode = RT_SPI_MODE_MASK | RT_SPI_MODE_1 | RT_SPI_MSB ; //Configure as spi master, MODE1 (CPOL=0,CPHA=1)

I feel like there is a problem with the two coordinations: the configuration of drv_spi.c is:

switch(configuration->mode & RT_SPI_MODE_3)
{
case RT_SPI_MODE_0:
SPI_InitStructure.CLKPOL = SPI_CLKPOL_LOW;
SPI_InitStructure.CLKPHA = SPI_CLKPHA_FIRST_EDGE;
break;
case RT_SPI_MODE_1:
SPI_InitStructure.CLKPOL = SPI_CLKPOL_LOW;
SPI_InitS structure.CLKPHA = SPI_CLKPHA_SECOND_EDGE;
break;
case RT_SPI_MODE_2:
SPI_InitStructure.CLKPOL = SPI_CLKPOL_HIGH;
SPI_InitStructure.CLKPHA = SPI_CLKPHA_FIRST_EDGE;
break;
case RT_SPI_MODE_3:
SPI_InitStructure.CLKPOL = SPI_CLKPOL_HIGH;
SPI_InitStructure.CLKPHA = SPI_CLKPHA_SECOND_EDGE;
break;
}

Is it possible not to pass all three parameters together, because the following configuration parameters directly specify several parameters:

/*!< SPI configuration */
SPI_InitStructure.DataDirection = SPI_DIR_SINGLELINE_TX;
SPI_InitStructure.SpiMode = SPI_MODE_MASTER;
SPI_InitStructure.CLKPHA = SPI_CLKPHA_SECOND_EDGE;
SPI_InitStructure.NSS = SPI_NSS_SOFT;
SPI_InitStructure.CRCPoly = 7;

So I changed the mode configuration to:

cfg.mode = RT_SPI_MODE_1;

After downloading, check the timing diagram as follows:

It feels like we have made another step forward, the data sent by spi is already available.

But only one bit of data was sent, and it was not the number I sent.

I looked back and found that the order of data transmission was not specified:

Updated to:

cfg.mode = RT_SPI_MODE_1 | RT_SPI_MSB;

The timing diagram after downloading is as follows:

The data sent out is correct, but it is stuck at FlagStatus SPI_I2S_GetStatus(SPI_Module* SPIx, uint16_t SPI_I2S_FLAG);.

It seems there is a configuration problem somewhere.

After debugging again, I found that it was stuck at the waiting for reception mark. I originally sent the command but only sent it, but did not receive it. This...

Go back and modify the configuration function of drv_spi.c again:

/*!< SPI configuration */
SPI_InitStructure.DataDirection = SPI_DIR_DOUBLELINE_FULLDUPLEX; //Change to duplex again

Then send successfully:

So far, the spi transmission has been adjusted:

Final summary:

1. The structure of receiving cs in configure(struct rt_spi_device* device, struct rt_spi_configuration* configuration) of drv_spi.c should be set as follows:

struct n32_hw_spi_cs
{
GPIO_Module* GPIOx;
uint32_t GPIO_Pin;
};

Also, the mode parameter passed in cannot be added to the master-slave mode.

Only can be sent:

cfg.mode = RT_SPI_MODE_1 | RT_SPI_MSB; these two parameters

Finally, upload the project. I hope this will give some suggestions to those who want to use RT_Thread Studio with N32G45.

Adjust the transmission rate to 70M and test it. The actual working frequency is 50M as the maximum frequency.

Jacktang

Can't the mode parameter passed in in the final summary be added to the master-slave mode?

Thank you for the suggestion

lugl4313820

Jacktang posted on 2022-2-8 07:25 Can't the mode parameter passed in the final summary be added to the master-slave mode? Thank you for your suggestion

Actually, this drv_spi.c driver is provided by netizens. Currently, I have not seen any drv_spi.c driver provided by National Technology. It is hard-coded in drv_spi.c that it can only work in master mode. Many configurations can only be modified manually, including NSS mode.