Chip-specific system clock management functions.
Copyright (c) 2011-2018 Microchip Technology Inc. and its subsidiaries.
Macros | |
#define | CONFIG_USBCLK_DIV |
Configuration symbol for the USB generic clock divider setting. More... | |
#define | CONFIG_USBCLK_SOURCE |
Configuration symbol for the USB generic clock source. More... | |
Configuration Symbols | |
#define | CONFIG_SYSCLK_SOURCE SYSCLK_SRC_MAINCK_4M_RC |
Initial/static main system clock source. More... | |
#define | CONFIG_SYSCLK_PRES 0 |
Initial CPU clock divider (mck) More... | |
Master Clock Sources (MCK) | |
#define | SYSCLK_SRC_SLCK_RC 0 |
Internal 32kHz RC oscillator as master source clock. More... | |
#define | SYSCLK_SRC_SLCK_XTAL 1 |
External 32kHz crystal oscillator as master source clock. More... | |
#define | SYSCLK_SRC_SLCK_BYPASS 2 |
External 32kHz bypass oscillator as master source clock. More... | |
#define | SYSCLK_SRC_MAINCK_4M_RC 3 |
Internal 4MHz RC oscillator as master source clock. More... | |
#define | SYSCLK_SRC_MAINCK_8M_RC 4 |
Internal 8MHz RC oscillator as master source clock. More... | |
#define | SYSCLK_SRC_MAINCK_12M_RC 5 |
Internal 12MHz RC oscillator as master source clock. More... | |
#define | SYSCLK_SRC_MAINCK_XTAL 6 |
External crystal oscillator as master source clock. More... | |
#define | SYSCLK_SRC_MAINCK_BYPASS 7 |
External bypass oscillator as master source clock. More... | |
#define | SYSCLK_SRC_PLLACK 8 |
Use PLLACK as master source clock. More... | |
#define | SYSCLK_SRC_UPLLCK 9 |
Use UPLLCK as master source clock. More... | |
Master Clock Prescalers (MCK) | |
#define | SYSCLK_PRES_1 PMC_MCKR_PRES_CLK_1 |
Set master clock prescaler to 1. More... | |
#define | SYSCLK_PRES_2 PMC_MCKR_PRES_CLK_2 |
Set master clock prescaler to 2. More... | |
#define | SYSCLK_PRES_4 PMC_MCKR_PRES_CLK_4 |
Set master clock prescaler to 4. More... | |
#define | SYSCLK_PRES_8 PMC_MCKR_PRES_CLK_8 |
Set master clock prescaler to 8. More... | |
#define | SYSCLK_PRES_16 PMC_MCKR_PRES_CLK_16 |
Set master clock prescaler to 16. More... | |
#define | SYSCLK_PRES_32 PMC_MCKR_PRES_CLK_32 |
Set master clock prescaler to 32. More... | |
#define | SYSCLK_PRES_64 PMC_MCKR_PRES_CLK_64 |
Set master clock prescaler to 64. More... | |
#define | SYSCLK_PRES_3 PMC_MCKR_PRES_CLK_3 |
Set master clock prescaler to 3. More... | |
USB Clock Sources | |
#define | USBCLK_SRC_PLL0 0 |
Use PLLA. More... | |
#define | USBCLK_SRC_UPLL 1 |
Use UPLL. More... | |
Functions | |
void | sysclk_disable_usb (void) |
Disable full speed USB clock. More... | |
void | sysclk_enable_usb (void) |
Enable full speed USB clock. More... | |
Querying the system clock | |
The following functions may be used to query the current frequency of the system clock and the CPU and bus clocks derived from it. sysclk_get_main_hz() and sysclk_get_cpu_hz() can be assumed to be available on all platforms, although some platforms may define additional accessors for various chip-internal bus clocks. These are usually not intended to be queried directly by generic code. | |
static uint32_t | sysclk_get_main_hz (void) |
Return the current rate in Hz of the main system clock. 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_peripheral_hz (void) |
Retrieves the current rate in Hz of the peripheral clocks. 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... | |
Enabling and disabling synchronous clocks | |
static void | sysclk_enable_peripheral_clock (uint32_t ul_id) |
Enable a peripheral's clock. More... | |
static void | sysclk_disable_peripheral_clock (uint32_t ul_id) |
Disable a peripheral's clock. More... | |
System Clock Source and Prescaler configuration | |
void | sysclk_set_prescalers (uint32_t ul_pres) |
Set system clock prescaler configuration. More... | |
void | sysclk_set_source (uint32_t ul_src) |
Change the source of the main system clock. More... | |
System Clock Initialization | |
void | sysclk_init (void) |
Initialize the synchronous clock system. More... | |