mega/sysclk.h File Reference

Chip-specific system clock management functions.

Copyright (c) 2014-2018 Microchip Technology Inc. and its subsidiaries.

#include <board.h>
#include <compiler.h>
#include <parts.h>
#include <conf_clock.h>

Macros
#define	ASM   __asm__
#define	CONFIG_SYSCLK_PSDIV   SYSCLK_PSDIV_8
#define	PRADC_bm   1 << PRADC
#define	PRSPI_bm   1 << PRSPI
#define	PRTIM0_bm   1 << PRTIM0
#define	PRTIM1_bm   1 << PRTIM1
#define	PRTIM2_bm   1 << PRTIM2
#define	PRTWI_bm   1 << PRTWI
#define	PRUSART0_bm   1 << PRUSART0
#define	SYSCLK_PSDIV_1   0 /* !< Do not prescale */
#define	SYSCLK_PSDIV_2   1 /* !< Prescale CLKper4 by 2 */
#define	SYSCLK_PSDIV_4   2 /* !< Prescale CLKper4 by 4 */
#define	SYSCLK_PSDIV_8   3 /* !< Prescale CLKper4 by 8 */
#define	SYSCLK_PSDIV_16   4 /* !< Prescale CLKper4 by 16 */
#define	SYSCLK_PSDIV_32   5 /* !< Prescale CLKper4 by 32 */
#define	SYSCLK_PSDIV_64   6 /* !< Prescale CLKper4 by 64 */
#define	SYSCLK_PSDIV_128   7 /* !< Prescale CLKper4 by 128 */
#define	SYSCLK_PSDIV_256   8 /* !< Prescale CLKper4 by 256 */

Functions
Querying the system clock and its derived clocks
static uint32_t	sysclk_get_main_hz (void)
	Return the current rate in Hz of the main system clock To know the clock value at what frequency the main clock is running. More...
static uint32_t	sysclk_get_source_clock_hz (void)
	Return the current rate in Hz of source clock in Hz. More...
static uint32_t	sysclk_get_cpu_hz (void)
	Return the current rate in Hz of the CPU clock. More...
static uint32_t	sysclk_get_rc_osc_hz (void)
	Return the current rate in Hz of the clock from internal oscillator. More...
void	sysclk_enable_module (enum power_red_id port, uint8_t id)
	Enable the clock to peripheral id on port port. More...
void	sysclk_disable_module (enum power_red_id port, uint8_t id)
	Disable the clock to peripheral id on port port. More...
static void	sysclk_enable_peripheral_clock (const volatile void *module)
	Enable a peripherals clock from its base address. More...
static void	sysclk_disable_peripheral_clock (const volatile void *module)
	Disable a peripheral's clock from its base address. More...
static void	sysclk_set_prescalers (uint8_t psdiv)
	Set system clock prescaler configuration. More...
static uint32_t	sysclk_get_peripheral_bus_hz (const volatile void *module)
	Retrieves the current rate in Hz of the Peripheral Bus clock attached to the specified peripheral. More...
static bool	sysclk_module_is_enabled (enum power_red_id port, uint8_t id)
	Check if the synchronous clock is enabled for a module. More...
void	sysclk_init (void)
	Function to initialize the clock and disable clock for not required modules. More...

#define ASM   __asm__

Referenced by sysclk_set_prescalers().

#define CONFIG_SYSCLK_PSDIV   SYSCLK_PSDIV_8

Referenced by sysclk_get_rc_osc_hz(), sysclk_get_source_clock_hz(), sysclk_init(), and sysclk_set_prescalers().

#define PRADC_bm   1 << PRADC

Referenced by sysclk_disable_peripheral_clock(), and sysclk_enable_peripheral_clock().

#define PRSPI_bm   1 << PRSPI

Referenced by spi_master_init(), spi_slave_init(), sysclk_disable_peripheral_clock(), and sysclk_enable_peripheral_clock().

#define PRTIM0_bm   1 << PRTIM0

Referenced by sysclk_disable_peripheral_clock(), and sysclk_enable_peripheral_clock().

#define PRTIM1_bm   1 << PRTIM1

Referenced by sysclk_disable_peripheral_clock(), and sysclk_enable_peripheral_clock().

#define PRTIM2_bm   1 << PRTIM2

Referenced by sysclk_disable_peripheral_clock(), and sysclk_enable_peripheral_clock().

#define PRTWI_bm   1 << PRTWI

Referenced by sysclk_disable_peripheral_clock(), sysclk_enable_peripheral_clock(), and sysclk_get_peripheral_bus_hz().

#define PRUSART0_bm   1 << PRUSART0

Referenced by run_loopback_syncmode_test(), sysclk_disable_peripheral_clock(), sysclk_enable_peripheral_clock(), usart_enable_module_clock(), and usart_spi_init().

#define SYSCLK_PSDIV_1   0 /* !< Do not prescale */

Referenced by sysclk_get_rc_osc_hz(), sysclk_get_source_clock_hz(), and sysclk_set_prescalers().

#define SYSCLK_PSDIV_128   7 /* !< Prescale CLKper4 by 128 */

Referenced by sysclk_get_rc_osc_hz(), sysclk_get_source_clock_hz(), and sysclk_set_prescalers().

#define SYSCLK_PSDIV_16   4 /* !< Prescale CLKper4 by 16 */

Referenced by sysclk_get_rc_osc_hz(), sysclk_get_source_clock_hz(), and sysclk_set_prescalers().

#define SYSCLK_PSDIV_2   1 /* !< Prescale CLKper4 by 2 */

Referenced by sysclk_get_rc_osc_hz(), sysclk_get_source_clock_hz(), and sysclk_set_prescalers().

#define SYSCLK_PSDIV_256   8 /* !< Prescale CLKper4 by 256 */

Referenced by sysclk_get_rc_osc_hz(), sysclk_get_source_clock_hz(), and sysclk_set_prescalers().

#define SYSCLK_PSDIV_32   5 /* !< Prescale CLKper4 by 32 */

Referenced by sysclk_get_rc_osc_hz(), sysclk_get_source_clock_hz(), and sysclk_set_prescalers().

#define SYSCLK_PSDIV_4   2 /* !< Prescale CLKper4 by 4 */

Referenced by sysclk_get_rc_osc_hz(), sysclk_get_source_clock_hz(), and sysclk_set_prescalers().

#define SYSCLK_PSDIV_64   6 /* !< Prescale CLKper4 by 64 */

Referenced by sysclk_get_rc_osc_hz(), sysclk_get_source_clock_hz(), and sysclk_set_prescalers().

#define SYSCLK_PSDIV_8   3 /* !< Prescale CLKper4 by 8 */

Referenced by sysclk_get_rc_osc_hz(), sysclk_get_source_clock_hz(), sysclk_init(), and sysclk_set_prescalers().

void sysclk_disable_module	(	enum power_red_id	port,
		uint8_t	id
	)

Disable the clock to peripheral id on port port.

Parameters

port	ID of the port to which the module is connected (one of the power_red_id *definitions).
id	The ID (bit mask) of the peripheral module to be disabled.

References cpu_irq_restore(), and cpu_irq_save().

Referenced by sysclk_disable_peripheral_clock(), and sysclk_get_peripheral_bus_hz().

static void sysclk_disable_peripheral_clock ( const volatile void *  module )

inlinestatic

Disable a peripheral's clock from its base address.

Disables the clock to a peripheral, given its base address.

Parameters

module

Pointer to the module's base address.

References Assert, NULL, PRADC_bm, PRSPI_bm, PRTIM0_bm, PRTIM1_bm, PRTIM2_bm, PRTWI_bm, PRUSART0_bm, and sysclk_disable_module().

Referenced by get_temperature(), and tc_disable().

void sysclk_enable_module	(	enum power_red_id	port,
		uint8_t	id
	)

Enable the clock to peripheral id on port port.

Parameters

port	ID of the port to which the module is connected (one of the power_red_id *definitions).
id	The ID (bitmask) of the peripheral module to be disabled.*
port	ID of the port to which the module is connected (one of the power_red_id *definitions).
id	The ID (bitmask) of the peripheral module to be enabled.

References cpu_irq_restore(), and cpu_irq_save().

Referenced by run_loopback_syncmode_test(), spi_master_init(), spi_slave_init(), sysclk_enable_peripheral_clock(), usart_enable_module_clock(), and usart_spi_init().

static void sysclk_enable_peripheral_clock ( const volatile void *  module )

inlinestatic

Enable a peripherals clock from its base address.

Enables the clock to a peripheral, given its base address. If the peripheral has an associated clock on the HSB bus, this will be enabled also.

Parameters

module

Pointer to the module's base address.

References Assert, NULL, PRADC_bm, PRSPI_bm, PRTIM0_bm, PRTIM1_bm, PRTIM2_bm, PRTWI_bm, PRUSART0_bm, and sysclk_enable_module().

Referenced by adc_initialisation(), epd_spi_init(), get_temperature(), initialize_EPD_timer(), main(), PHY_Init(), PWM_start_toggle(), run_baudrate_set_test(), run_spi_transfer_test(), run_twi_master_recv_test(), run_twi_master_send_test(), sm_init(), tc_enable(), tfa_init(), timer2_initialisation(), trx_init(), twi_master_setup(), and twi_slave_setup().

static uint32_t sysclk_get_cpu_hz ( void  )

inlinestatic

Return the current rate in Hz of the CPU clock.

Returns

Frequency of the CPU clock, in Hz.

References sysclk_get_source_clock_hz().

Referenced by main(), run_baudrate_test(), run_spi_transfer_test(), run_twi_master_recv_test(), run_twi_master_send_test(), spi_master_setup_device(), and twi_master_setup().

static uint32_t sysclk_get_main_hz ( void  )

inlinestatic

Return the current rate in Hz of the main system clock To know the clock value at what frequency the main clock is running.

Returns

Frequency of the main system clock, in Hz.

Todo:

: please initialize the SYSCLK_SOURCE in conf_clock.h file for configured source clock using fuses. . #define SYSCLK_SOURCE SYSCLK_SRC_RC16MHZ to use internal RC oscillator for clock source.

Referenced by sysclk_get_rc_osc_hz(), and sysclk_get_source_clock_hz().

static uint32_t sysclk_get_peripheral_bus_hz ( const volatile void *  module )

inlinestatic

Retrieves the current rate in Hz of the Peripheral Bus clock attached to the specified peripheral.

Parameters

module

Pointer to the module's base address.

Returns

Frequency of the bus attached to the specified peripheral, in Hz.

References Assert, NULL, PRTWI_bm, sysclk_disable_module(), and sysclk_get_source_clock_hz().

Referenced by initialize_EPD_timer(), PWM_start_toggle(), and tmr_init().

static uint32_t sysclk_get_rc_osc_hz ( void  )

inlinestatic

Return the current rate in Hz of the clock from internal oscillator.

Returns

Frequency of the CPU clock, in Hz.

References CONFIG_SYSCLK_PSDIV, sysclk_get_main_hz(), SYSCLK_PSDIV_1, SYSCLK_PSDIV_128, SYSCLK_PSDIV_16, SYSCLK_PSDIV_2, SYSCLK_PSDIV_256, SYSCLK_PSDIV_32, SYSCLK_PSDIV_4, SYSCLK_PSDIV_64, and SYSCLK_PSDIV_8.

static uint32_t sysclk_get_source_clock_hz ( void  )

inlinestatic

Return the current rate in Hz of source clock in Hz.

This clock always runs at the same rate as the CPU clock unless the divider is set.

Returns

Frequency of the system clock, in Hz.

References CONFIG_SYSCLK_PSDIV, sysclk_get_main_hz(), SYSCLK_PSDIV_1, SYSCLK_PSDIV_128, SYSCLK_PSDIV_16, SYSCLK_PSDIV_2, SYSCLK_PSDIV_256, SYSCLK_PSDIV_32, SYSCLK_PSDIV_4, SYSCLK_PSDIV_64, and SYSCLK_PSDIV_8.

Referenced by run_loopback_syncmode_test(), sysclk_get_cpu_hz(), sysclk_get_peripheral_bus_hz(), usart_init_rs232(), and usart_init_spi().

static bool sysclk_module_is_enabled ( enum power_red_id  port, uint8_t  id  )

inlinestatic

Check if the synchronous clock is enabled for a module.

Parameters

port	ID of the port to which the module is connected (one of the SYSCLK_PORT_* definitions).
id	The ID (bitmask) of the peripheral module to check (one of the SYSCLK_* module definitions).

Return values

true	If the clock for module id on port is enabled.
false	If the clock for module id on port is disabled.

static void sysclk_set_prescalers ( uint8_t  psdiv )

inlinestatic

Set system clock prescaler configuration.

This function will change the system clock prescaler configuration to match the parameters.

Note

The parameters to this function are device-specific.

Parameters

psbcdiv

The prescaler settings (one of the SYSCLK_PSCDIV_* definitions). These determine the clkIO, clkADC and clkCPU frequencies. Note: Prescaler setting is not working with the brain dead un optimised code e.g. avr-gcc -00

References ASM, CONFIG_SYSCLK_PSDIV, cpu_irq_restore(), cpu_irq_save(), SYSCLK_PSDIV_1, SYSCLK_PSDIV_128, SYSCLK_PSDIV_16, SYSCLK_PSDIV_2, SYSCLK_PSDIV_256, SYSCLK_PSDIV_32, SYSCLK_PSDIV_4, SYSCLK_PSDIV_64, and SYSCLK_PSDIV_8.

Referenced by sysclk_init().