SPI clock cannot be detected

Hi,

We are using DA14580DEVKT-B. We try to use SPI interface to transmit data from accelerometer to DA14580 chip, and then send data via BLE.

However, the SPI clock signal can not be detected from P0_0, even though we have configure as follow (We are using ble_app_peripheral sample in SDK):

SetBits16(CLK_PER_REG, SPI_ENABLE, 1);

// initialize SPI
SetBits16(SPI_CTRL_REG, SPI_ON, 0); // close SPI block, if opened
SetBits16(SPI_CTRL_REG, SPI_WORD, bitmode); // set SPI bitmode
SetBits16(SPI_CTRL_REG, SPI_SMN, role); // select role (master/slave)
SetBits16(SPI_CTRL_REG, SPI_POL, clk_pol); // select SPI clock idle polarity
SetBits16(SPI_CTRL_REG, SPI_PHA, pha_mode); // select SPI sampling edge selection (pha_mode - refer to datasheet p.53-54)
SetBits16(SPI_CTRL_REG, SPI_MINT, irq); // enable/disable SPI interrupt to the NVIC
SetBits16(SPI_CTRL_REG, SPI_CLK, freq); // SPI block clock divider
SetBits16(SPI_CTRL_REG, SPI_ON, 1); // enable SPI block

GPIO_ConfigurePin(SPI_GPIO_PORT, SPI_CS_PIN, OUTPUT, PID_SPI_EN, true);
GPIO_ConfigurePin(SPI_GPIO_PORT, SPI_CLK_PIN, OUTPUT, PID_SPI_CLK,false);
GPIO_ConfigurePin(SPI_GPIO_PORT, SPI_DO_PIN, OUTPUT, PID_SPI_DO, false);
GPIO_ConfigurePin(SPI_GPIO_PORT, SPI_DI_PIN, INPUT, PID_SPI_DI, false);

Then, we wanted to figure out what was wrong such that we tried to run blinky and SPI_flash. The SPI clock signal can be seen as suqare wave from P0_0 as the same configuration above.

However, no matter how we changed the SPI_CLK of SPI_CTRL_REG from 00 to 11, the clock frequency cannot be changed.

code: SetBits16(SPI_CTRL_REG, SPI_CLK, freq);

Even, we changed all the codes in blinky one by one, the clock signal remain unchanged. So we are so confused about the spi clock signal on how to generate and be changed?

Thanks.