usart_synchronous_example.c File Reference

USART Synchronous example for SAM.

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

#include <string.h>
#include "asf.h"
#include "stdio_serial.h"
#include "conf_board.h"
#include "conf_clock.h"
#include "conf_example.h"

Macros
#define	ALL_INTERRUPT_MASK   0xffffffff
	All interrupt mask. More...
#define	BUFFER_SIZE   2000
	size of the receive buffer used by the PDC, in bytes. More...
#define	FREQ_OPTIONS_NUM   4
#define	STATE_READ   0
	USART is reading. More...
#define	STATE_WRITE   1
	USART is writing. More...
#define	STRING_EOL   "\r"
#define	STRING_HEADER
#define	SYNC_MASTER   1
	USART synchronous master. More...
#define	SYNC_SLAVE   0
	USART synchronous slave. More...

Functions
static void	configure_console (void)
	Configure UART for debug message output. More...
static void	configure_usart (uint32_t ul_ismaster, uint32_t ul_baudrate)
	Configure USART in synchronous mode. More...
static void	display_main_menu (void)
	Display main menu. More...
static void	dump_info (char *p_buf, uint32_t ul_size)
	Dump buffer to uart. More...
int	main (void)
	Application entry point. More...
void	USART_Handler (void)
	USART IRQ handler. More...

Variables
int8_t	g_c_recv_buff [BUFFER_SIZE] = { 0 }
	Buffer for receiving. More...
Pdc *	g_p_pdc
	Pointer to PDC register base. More...
pdc_packet_t	g_st_packet
	PDC data packet. More...
uint8_t	g_uc_freq_idx = 0
	Present frequency index in list g_ul_freq[]. More...
uint8_t	g_uc_state = STATE_WRITE
	State of reading or writing. More...
uint8_t	g_uc_transfer_mode = SYNC_MASTER
	Mode for usart, 0 means usart as slave and 1 for master. More...
uint32_t	g_ul_freq [FREQ_OPTIONS_NUM]
	Clock freq. More...
volatile uint32_t	g_ul_recv_done = false
	Reception is done. More...
volatile uint32_t	g_ul_sent_done = false
	Sending is done. More...
char	tran_buff [BUFFER_SIZE]
	Transmit buffer. More...

#define ALL_INTERRUPT_MASK   0xffffffff

All interrupt mask.

Referenced by configure_usart().

#define BUFFER_SIZE   2000

size of the receive buffer used by the PDC, in bytes.

Referenced by main().

#define FREQ_OPTIONS_NUM   4

#define STATE_READ   0

USART is reading.

Referenced by main(), and USART_Handler().

#define STATE_WRITE   1

USART is writing.

Referenced by main(), and USART_Handler().

#define STRING_EOL   "\r"

#define STRING_HEADER

Value:

"--USART Synchronous Mode Example --\r\n" \
        "-- "BOARD_NAME" --\r\n" \
        "-- Compiled: "__DATE__" "__TIME__" --"STRING_EOL

Referenced by main().

#define SYNC_MASTER   1

USART synchronous master.

Referenced by main().

#define SYNC_SLAVE   0

USART synchronous slave.

Referenced by main().

static void configure_console ( void  )

static

Configure UART for debug message output.

References uart_rs232_options::baudrate, stdio_serial_init(), and sysclk_enable_peripheral_clock().

Referenced by main().

static void configure_usart ( uint32_t  ul_ismaster, uint32_t  ul_baudrate  )

static

Configure USART in synchronous mode.

Parameters

ul_ismaster	1 for master, 0 for slave.
ul_baudrate	Baudrate for synchronous communication.

References ALL_INTERRUPT_MASK, sam_usart_opt_t::baudrate, sysclk_enable_peripheral_clock(), sysclk_get_peripheral_hz(), usart_disable_interrupt(), usart_enable_rx(), usart_enable_tx(), usart_init_sync_master(), and usart_init_sync_slave().

Referenced by main().

static void display_main_menu ( void  )

static

Display main menu.

Referenced by main().

static void dump_info ( char *  p_buf, uint32_t  ul_size  )

static

Dump buffer to uart.

Referenced by main().

int main

(

void

)

Application entry point.

Configure USART in synchronous master/slave mode to start a transmission between two boards.

Returns

Unused.

References board_init(), BUFFER_SIZE, configure_console(), configure_usart(), display_main_menu(), dump_info(), g_c_recv_buff, g_p_pdc, g_uc_freq_idx, g_uc_state, g_uc_transfer_mode, g_ul_freq, g_ul_recv_done, g_ul_sent_done, NULL, pdc_enable_transfer(), pdc_rx_init(), pdc_tx_init(), STATE_READ, STATE_WRITE, STRING_HEADER, SYNC_MASTER, SYNC_SLAVE, sysclk_init(), tran_buff, pdc_packet::ul_addr, pdc_packet::ul_size, usart_enable_interrupt(), and usart_get_pdc_base().

void USART_Handler

(

void

)

USART IRQ handler.

Interrupt handler for USART. After reception is done, set g_ul_recv_done to true, and if transmission is done, set g_ul_sent_done to true.

References g_uc_state, g_ul_recv_done, g_ul_sent_done, STATE_READ, STATE_WRITE, usart_disable_interrupt(), and usart_get_status().

int8_t g_c_recv_buff[BUFFER_SIZE] = { 0 }

Buffer for receiving.

Referenced by main().

Pdc* g_p_pdc

Pointer to PDC register base.

Referenced by main(), TC0_Handler(), usart_clear(), and USART_Handler().

pdc_packet_t g_st_packet

PDC data packet.

uint8_t g_uc_freq_idx = 0

Present frequency index in list g_ul_freq[].

Referenced by main().

uint8_t g_uc_state = STATE_WRITE

State of reading or writing.

Referenced by main(), refresh_display(), and USART_Handler().

uint8_t g_uc_transfer_mode = SYNC_MASTER

Mode for usart, 0 means usart as slave and 1 for master.

Referenced by main().

uint32_t g_ul_freq[FREQ_OPTIONS_NUM]

Initial value:

=
        { 1000000UL, 4000000UL, 10000000UL, 16000000UL }

Clock freq.

Referenced by main().

volatile uint32_t g_ul_recv_done = false

Reception is done.

Referenced by main(), and USART_Handler().

volatile uint32_t g_ul_sent_done = false

Sending is done.

Referenced by main(), and USART_Handler().

char tran_buff[BUFFER_SIZE]

Initial value:

= "DESCRIPTION of this example: \r\n \
 **************************************************************************\r\n\
 *  This application gives an example of how to use USART in synchronous mode.\r\n\
 *  Synchronous operations provide a high speed transfer capability. The\r\n\
 *  transfer under this mode needs a pair of master and slave, which is\r\n\
 *  determined by which one offers the clock source.\r\n\
 *  \r\n\
 *  The example initialized USART as master by default. To enable the \r\n\
 *  communication between each side of the connection. The user should change\r\n\
 *  the mode of another side to slave through user interface. If well configured,\r\n\
 *  transfer could be started by typing 'r' and  'w' from terminal application.\r\n\
 *  This example also leaves the interface to select the clock freq.\r\n\
 *  \r\n\
 *  The meaning of each input character could be found in items of the main menu.\r\n\
 *  \r\n\
 **************************************************************************\r\n\
 END of DESCRIPTION \r\n\
 "

Transmit buffer.

Referenced by main().