pmc_clock_switching_example.c File Reference

PMC Clock Switching example for SAM.

Copyright (c) 2011-2018 Microchip Technology Inc. and its subsidiaries.

#include "asf.h"
#include "stdio_serial.h"
#include "conf_board.h"
#include "conf_pmc_clock_switching_example.h"

Macros
#define	GCLK_ID   PMC_PCK_0
	Programmable Clock ID for the example by default. More...
#define	GCLK_PIN   PIN_PCK0
	Programmable Clock Pin for the example by default. More...
#define	GCLK_PIN_MUX   PIN_PCK0_MUX
	Programmable Clock Pin Mux for the example by default. More...
#define	PMC_CLOCK_SWITCHING_EXAMPLE_BAUDRATE   (2400)
	PMC External Xtal 12Mhz. More...
#define	PMC_CLOCK_SWITCHING_EXAMPLE_FIXED_PLLA   (8192000)
	Fixed PLLA test clock, 8.192Mhz. More...
#define	PMC_PCK_PRES_CLK_1   PMC_PCK_PRES(0)
#define	PMC_PCK_PRES_CLK_16   PMC_PCK_PRES(4)
#define	PMC_PCK_PRES_CLK_2   PMC_PCK_PRES(1)
#define	PMC_PCK_PRES_CLK_32   PMC_PCK_PRES(5)
#define	PMC_PCK_PRES_CLK_4   PMC_PCK_PRES(2)
#define	PMC_PCK_PRES_CLK_64   PMC_PCK_PRES(6)
#define	PMC_PCK_PRES_CLK_8   PMC_PCK_PRES(3)
#define	STRING_EOL   "\r"
#define	STRING_HEADER

Functions
static void	button1_handler (uint32_t ul_id, uint32_t ul_mask)
	Handler for Button 1 rising edge interrupt. More...
static void	config_uart_and_pck (uint32_t ul_clock_source, uint32_t ul_prescaler, uint32_t ul_master_clock)
	Configure UART with the given master clock, and Configure PCK with the given divider source of master clock and prescaler. More...
static void	configure_buttons (void)
	Configure the Push buttons. More...
static void	configure_console (void)
	Configure the Console Uart. More...
int	main (void)
	Application entry point for pmc_clock switch example. More...

Variables
static volatile uint8_t	gs_uc_wait_button = 0
	User push button activated flag. More...

#define GCLK_ID   PMC_PCK_0

Programmable Clock ID for the example by default.

Referenced by config_uart_and_pck().

#define GCLK_PIN   PIN_PCK0

Programmable Clock Pin for the example by default.

Referenced by main().

#define GCLK_PIN_MUX   PIN_PCK0_MUX

Programmable Clock Pin Mux for the example by default.

Referenced by main().

#define PMC_CLOCK_SWITCHING_EXAMPLE_BAUDRATE   (2400)

PMC External Xtal 12Mhz.

Referenced by config_uart_and_pck().

#define PMC_CLOCK_SWITCHING_EXAMPLE_FIXED_PLLA   (8192000)

Fixed PLLA test clock, 8.192Mhz.

Referenced by main().

#define PMC_PCK_PRES_CLK_1   PMC_PCK_PRES(0)

Referenced by main().

#define PMC_PCK_PRES_CLK_16   PMC_PCK_PRES(4)

Referenced by main().

#define PMC_PCK_PRES_CLK_2   PMC_PCK_PRES(1)

Referenced by main().

#define PMC_PCK_PRES_CLK_32   PMC_PCK_PRES(5)

#define PMC_PCK_PRES_CLK_4   PMC_PCK_PRES(2)

#define PMC_PCK_PRES_CLK_64   PMC_PCK_PRES(6)

#define PMC_PCK_PRES_CLK_8   PMC_PCK_PRES(3)

#define STRING_EOL   "\r"

#define STRING_HEADER

Value:

"-- Pmc Clock Switching Example --\r\n" \
        "-- "BOARD_NAME" --\r\n" \
        "-- Compiled: "__DATE__" "__TIME__" --"STRING_EOL

Referenced by main().

static void button1_handler ( uint32_t  ul_id, uint32_t  ul_mask  )

static

Handler for Button 1 rising edge interrupt.

Handle process led1 status change.

References gs_uc_wait_button, PIN_PUSHBUTTON_1_ID, and PIN_PUSHBUTTON_1_MASK.

Referenced by configure_buttons().

static void config_uart_and_pck ( uint32_t  ul_clock_source, uint32_t  ul_prescaler, uint32_t  ul_master_clock  )

static

Configure UART with the given master clock, and Configure PCK with the given divider source of master clock and prescaler.

Parameters

ul_clock_source	The master clock divider source.
ul_prescaler	Master Clock prescaler.
ul_master_clock	Frequency of the master clock (in Hz).

References sam_usart_opt_t::baudrate, BOARD_FREQ_SLCK_XTAL, sam_usart_opt_t::channel_mode, sam_usart_opt_t::char_length, CONF_UART_CHAR_LENGTH, CONF_UART_PARITY, CONF_UART_STOP_BITS, CONFIG_SYSCLK_DIV, CONSOLE_UART, CONSOLE_UART_ID, GCLK_ID, sam_usart_opt_t::parity_type, PMC_CLOCK_SWITCHING_EXAMPLE_BAUDRATE, pmc_disable_pck(), pmc_enable_pck(), pmc_enable_periph_clk(), pmc_switch_pck_to_mainck(), pmc_switch_pck_to_pllack(), pmc_switch_pck_to_pllbck(), pmc_switch_pck_to_sclk(), sam_usart_opt_t::stop_bits, uart_init(), usart_enable_rx(), usart_enable_tx(), and usart_init_rs232().

Referenced by main().

static void configure_buttons ( void  )

static

Configure the Push buttons.

Configure the PIO as inputs and generate corresponding interrupt when pressed or released.

References button1_handler(), PIN_PUSHBUTTON_1_ATTR, PIN_PUSHBUTTON_1_ID, PIN_PUSHBUTTON_1_MASK, PIN_PUSHBUTTON_1_PIO, pio_enable_interrupt(), pio_handler_set(), pio_set_debounce_filter(), and pmc_enable_periph_clk().

Referenced by main().

static void configure_console ( void  )

static

Configure the Console Uart.

References uart_rs232_options::baudrate, CONF_UART, CONF_UART_BAUDRATE, CONF_UART_CHAR_LENGTH, CONF_UART_PARITY, CONF_UART_STOP_BITS, CONSOLE_UART_ID, stdio_serial_init(), and sysclk_enable_peripheral_clock().

Referenced by main().

int main

(

void

)

Application entry point for pmc_clock switch example.

Returns

Unused (ANSI-C compatibility).

References BOARD_FREQ_MAINCK_XTAL, BOARD_FREQ_SLCK_XTAL, board_init(), BOARD_OSC_STARTUP_US, BUTTON_NAME, CONF_UART, config_uart_and_pck(), configure_buttons(), configure_console(), GCLK_PIN, GCLK_PIN_MUX, gs_uc_wait_button, ioport_disable_pin(), ioport_set_pin_mode(), PMC_CLOCK_SWITCHING_EXAMPLE_FIXED_PLLA, pmc_disable_pllbck(), pmc_enable_pllack(), pmc_enable_pllbck(), PMC_OSC_XTAL, PMC_PCK_PRES_CLK_1, PMC_PCK_PRES_CLK_16, PMC_PCK_PRES_CLK_2, pmc_switch_mainck_to_fastrc(), pmc_switch_mainck_to_xtal(), pmc_switch_mck_to_mainck(), pmc_switch_mck_to_pllack(), pmc_switch_mck_to_pllbck(), pmc_switch_mck_to_sclk(), pmc_switch_sclk_to_32kxtal(), STRING_HEADER, sysclk_init(), uart_is_tx_empty(), and usart_is_tx_empty().

volatile uint8_t gs_uc_wait_button = 0

static

User push button activated flag.

Referenced by button1_handler(), and main().