Description

The i.MXxx HAL provides a number of macros to support the management of peripheral clocks. The macro CYGHWR_HAL_IMX_CLOCK( cgcr, device ) encodes a clock control descriptor into a 32 bit value. The arguments are the clock group register name, and the name of the clock to be controlled.

The remaining functions all take a peripheral clock descriptor as an argument. CYGHWR_HAL_IMX_CLOCK_ENABLE( desc ) enables the given clock. Likewise CYGHWR_HAL_IMX_CLOCK_DISABLE( desc ) disables the clock.

The following examples show how a clock descriptor may be defined.

// EPIT input clock and EPIT1 device clock
#define CYGHWR_HAL_IMX_EPIT_PER_CLOCK   CYGHWR_HAL_IMX_CLOCK( CGCR0, PER_EPIT )
#define CYGHWR_HAL_IMX_EPIT1_CLOCK      CYGHWR_HAL_IMX_CLOCK( CGCR1, IPG_EPIT1 )

// UART1 clock
#define CYGHWR_HAL_IMX_UART1_CLOCK      CYGHWR_HAL_IMX_CLOCK( CGCR2, IPG_UART1 )