SPIM 3 at 16MHz

[siri sam]

Hello,

I'm using SPI 3 to communicate with a NAND memory. I'm able to go up to 8MHz but not more than that. Do I need to set an array list or use the spi manager. 

Is there any exemple of the spi going up to 16Mhz?

Best regards

[Einar Thorsrud]

Hi,

There is no example of SPIM3 with speeds > 8 MHz. It is supported by the HW, but you have to adapt the driver slightly as it only supports up to 8 MHz. Note that that you should read the errata list if you use SPIM3 as there is quite a few issues with it.

[siri sam]

Hello,

I have seen the thread  about the SPIM3->IFTIMING.RXDELAY and i've set it to 2 but it doesn't work either.  Do you have more information about how I should adapt the driver? I have activated the anomaly 198 workaround but no success.

 

[Einar Thorsrud]

Fast SPIM is only functional on the final silicon. Are you using a engineering sample (for instance preview DK) or do you have revision 1? (What is the marking on the chip?)

[siri sam]

We are using the revision 1. We also have some revision B but as it is describe on some other thread it seems to works with this one too no?

Anyway all our product are with the final revision.

[Einar Thorsrud]

I see, then all should be good. Can you let me know which SDK you are using and how you have configured and are using the SPIM3 peripheral? Seeing your code would be helpful. In what way does it not work?

[siri sam]

We are using the SDK 15, I'm now migrating to the 15.2. The device work fine at 8Mhz but to optimize our device, we need to go up to 16Mhz. 

here is the init part in our code : 

void init_spi() {

// CS output
nrf_gpio_cfg_output(SPI_CS);

nrfx_spim_config_t config = NRFX_SPIM_DEFAULT_CONFIG;

config.sck_pin = SPI_SCK;
config.miso_pin = SPI_MISO;
config.mosi_pin = SPI_MOSI;
config.rx_delay = 2;
config.frequency = NRF_SPIM_FREQ_8M; // max working frequency
config.irq_priority =2;


config.mode = NRF_SPIM_MODE_0;

nrf_gpio_cfg_default(IO_NAND_IO0);
nrf_gpio_cfg_default(IO_NAND_IO1);
nrf_gpio_cfg_output(IO_NAND_IO2);
nrf_gpio_cfg_output(IO_NAND_IO3);
nrf_gpio_pin_write(IO_NAND_IO2, 1);
nrf_gpio_pin_write(IO_NAND_IO3, 1);


uint32_t err_code = nrfx_spim_init(&m_spi, &config, spi_event_handler, NULL);

}

Thanks for your help

[Einar Thorsrud]

I see. What happens when you set "config.frequency = NRF_SPIM_FREQ_16M;" this instead? In what way does things fail?

[siri sam]

when I set SPIM at 16Mz, there is no clk generated anymore but the firmware is still running background.

[Einar Thorsrud]

I have not been able to reproduce this on my side. I have modified the SDK 15.2 SPI example to use SPIM3 and the nrfx driver and 16 MHz, and this works as expected on my side.

This is my main.c and sdk_config.h file: 

Fullscreen main.c Download

/**
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 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form, except as embedded into a Nordic
 *    Semiconductor ASA integrated circuit in a product or a software update for
 *    such product, must reproduce the above copyright notice, this list of
 *    conditions and the following disclaimer in the documentation and/or other
 *    materials provided with the distribution.
 *
 * 3. Neither the name of Nordic Semiconductor ASA nor the names of its
 *    contributors may be used to endorse or promote products derived from this
 *    software without specific prior written permission.
 *
 * 4. This software, with or without modification, must only be used with a
 *    Nordic Semiconductor ASA integrated circuit.
 *
 * 5. Any software provided in binary form under this license must not be reverse
 *    engineered, decompiled, modified and/or disassembled.
 *
 * THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */
#include "nrf_drv_spi.h"
#include "app_util_platform.h"
#include "nrf_gpio.h"
#include "nrf_delay.h"
#include "boards.h"
#include "app_error.h"
#include <string.h>
#include "nrf_log.h"
#include "nrf_log_ctrl.h"
#include "nrf_log_default_backends.h"

#define SPI_INSTANCE  3 /**< SPI instance index. */
static const nrfx_spim_t spi = NRFX_SPIM_INSTANCE(SPI_INSTANCE);  /**< SPI instance. */
static volatile bool spi_xfer_done;  /**< Flag used to indicate that SPI instance completed the transfer. */

#define TEST_STRING "Nordic"
static uint8_t       m_tx_buf[] = TEST_STRING;           /**< TX buffer. */
static uint8_t       m_rx_buf[sizeof(TEST_STRING) + 1];    /**< RX buffer. */
static const uint8_t m_length = sizeof(m_tx_buf);        /**< Transfer length. */

/**
 * @brief SPI user event handler.
 * @param event
 */
void spi_event_handler(nrfx_spim_evt_t const * p_event,
                       void *                  p_context)
{
    spi_xfer_done = true;
    NRF_LOG_INFO("Transfer completed.");
    if (m_rx_buf[0] != 0)
    {
        NRF_LOG_INFO(" Received:");
        NRF_LOG_HEXDUMP_INFO(m_rx_buf, strlen((const char *)m_rx_buf));
    }
}

int main(void)
{
    bsp_board_init(BSP_INIT_LEDS);

    APP_ERROR_CHECK(NRF_LOG_INIT(NULL));
    NRF_LOG_DEFAULT_BACKENDS_INIT();

    nrfx_spim_config_t spi_config = NRF_DRV_SPI_DEFAULT_CONFIG;
    spi_config.ss_pin    = SPI_SS_PIN;
    spi_config.miso_pin  = SPI_MISO_PIN;
    spi_config.mosi_pin  = SPI_MOSI_PIN;
    spi_config.sck_pin   = SPI_SCK_PIN;
    spi_config.frequency = SPIM_FREQUENCY_FREQUENCY_M16;
    APP_ERROR_CHECK(nrfx_spim_init(&spi, &spi_config, spi_event_handler, NULL));

    NRF_LOG_INFO("SPI example started.");

    while (1)
    {
        // Reset rx buffer and transfer done flag
        memset(m_rx_buf, 0, m_length);
        spi_xfer_done = false;

        nrfx_spim_xfer_desc_t xfer_desc = NRFX_SPIM_SINGLE_XFER(m_tx_buf, m_length, m_rx_buf, m_length);

        APP_ERROR_CHECK(nrfx_spim_xfer(&spi, &xfer_desc, 0));

        while (!spi_xfer_done)
        {
            __WFE();
        }

        NRF_LOG_FLUSH();

        bsp_board_led_invert(BSP_BOARD_LED_0);
        nrf_delay_ms(200);
    }
}

sdk_config.h

Can you upload your full source code including sck_config.h so that we can compare?