2.1. Clock tree

2.1.1. Introduction

The BL series chips have a lot of clock source selection and provide a clock tree configuration table to facilitate user configuration. Users do not need to call the clock setting interface. Users only need to care about the final system clock and peripheral clock frequency. The clock configuration table is located in the clock_config.h file under the bsp/board/xxx_board directory.

2.1.2. Clock Frequency Acquisition Interface

2.1.2.1. system_clock_get

system_clock_get is used to get the system clock frequency.

uint32_t system_clock_get(enum system_clock_type type);

• type the type of system clock frequency

type provide the following types

enum system_clock_type
{
    SYSTEM_CLOCK_ROOT_CLOCK = 0,
    SYSTEM_CLOCK_FCLK,
    SYSTEM_CLOCK_BCLK,
    SYSTEM_CLOCK_XCLK,
    SYSTEM_CLOCK_32K_CLK,
    SYSTEM_CLOCK_AUPLL,
};

2.1.2.2. peripheral_clock_get

peripheral_clock_get is used to get the peripheral clock frequency.

uint32_t peripheral_clock_get(enum peripheral_clock_type type);

• type peripheral clock frequency type

type provide the following types

enum peripheral_clock_type
{
    PERIPHERAL_CLOCK_UART = 0,
    PERIPHERAL_CLOCK_SPI,
    PERIPHERAL_CLOCK_I2C,
    PERIPHERAL_CLOCK_ADC,
    PERIPHERAL_CLOCK_DAC,
    PERIPHERAL_CLOCK_I2S,
    PERIPHERAL_CLOCK_PWM,
    PERIPHERAL_CLOCK_CAM,
};