spi clock problem

[john kotkin]

Hi,

I'm trying to use winbond spi flash (w25q64fv)

but i have a problem with spi as you can see in below image clock stop before receiving data from spi flash, do you have any idea why???

here is what should i see based on datasheet

here is my code for spi_master_init()

static void spi_master_init()
{
    uint32_t err_code = NRF_SUCCESS;

    // Configure SPI master.
    spi_master_config_t spi_config = SPI_MASTER_INIT_DEFAULT;

	spi_config.SPI_Pin_SCK  	= SPIM0_SCK_PIN;
	spi_config.SPI_Pin_MISO 	= SPIM0_MISO_PIN;
	spi_config.SPI_Pin_MOSI 	= SPIM0_MOSI_PIN;
	spi_config.SPI_Pin_SS   	= SPIM0_SS_PIN;

	spi_config.SPI_CONFIG_CPHA	= SPI_CONFIG_CPHA_Leading;
	spi_config.SPI_CONFIG_CPOL	= SPI_CONFIG_CPOL_ActiveHigh;
	
	spi_config.SPI_Freq			= SPI_FREQUENCY_FREQUENCY_K500;
	
    spi_config.SPI_CONFIG_ORDER = SPI_CONFIG_ORDER_MsbFirst;
	
    err_code = spi_master_open(SPI_MASTER_0, &spi_config);
    APP_ERROR_CHECK(err_code);

    // Register event handler for SPI master.
    spi_master_evt_handler_reg(SPI_MASTER_0, spi_master_0_event_handler);
}

void spi_master_0_event_handler(spi_master_evt_t spi_master_evt)
{
	// nothing
}

And here is my code for reading Status Register 1 (w25q64fv)

uint8_t readSR1() 
{ 
	uint8_t rx_data = 0x00;
	uint8_t tx_data[2] = {0x05, 0xff};
	
	spi_master_send_recv(SPI_MASTER_0, tx_data, 2, &rx_data, 1);
	
    return rx_data;
}

[nszmnsky]

The data sheet shows a 3 byte transaction, 1 byte command transmit and two byte receive. But to read a byte, you actually need to transmit one as SPI is a synchronous protocol. I think if you modify the code

uint8_t rx_data[3];

uint8_t tx_data[3] = {0x05, 0xff, 0xff};

spi_master_send_recv(SPI_MASTER_0, tx_data, 3, &rx_data, 3);

you should see 24 clocks, i.e. 3 byte send/receive. Of course you will also want to change function type and return IF you want 16bit integer.

[john kotkin]

I made this change and still nothing from w25q64fv, i changed my w25q64fv with a new one but still nothing

[nszmnsky]

I haven't used your flash, and I have only browsed the datasheet. Is it possible that the 0x05 should read register 1 would return all zero's? Try changing command to 0x90 to read the Manufact./Dev. ID (looks like would also need to change code to read 6 bytes) and see if you get correct data out.

I'd also suggest double checking pins - MOSI connected to DI, MISO to DO, and that /WP and /HOLD are pulled high.

[john kotkin]

Thank you, Yes the problem was because of two register i was trying to read return always Zero's