/* whether to stretch SCL low when data is not ready in slave mode  */
void i2c_stretch_scl_low_config(uint32_t i2c_periph, i2c_stretchscl_enum stretchpara)
/* whether to stretch SCL low when data is not ready in slave mode  */
void i2c_stretch_scl_low_config(uint32_t i2c_periph, i2c_stretchscl_enum stretchpara)
{
    I2C_CTL0(i2c_periph) &= ~(I2C_CTL0_DISSTRC);
    I2C_CTL0(i2c_periph) |= ((I2C_CTL0_DISSTRC)&(stretchpara));
}