PLC Buffered PDC USART

This module provides configuration and utils for PLC Buffered USART service interface.

Data Structures
struct	busart_comm_data_t
	Communications Queue Info. More...

Macros
#define	FREQ_TIMER_POLL_USART   100
#define	SERIAL_USART_0   0
#define	SERIAL_USART_1   1
#define	TIMER_USART_PRIO   10
#define	USART0_PRIO   10
#define	USART1_PRIO   10
#define	USART_BUFFER_SIZE   1024

Functions
int8_t	busart_if_close (uint8_t chn)
	This function closes and disables communication in the specified USART. More...
int8_t	busart_if_open (uint8_t chn, uint32_t bauds)
	This function opens an USART. More...
uint16_t	busart_if_read (uint8_t chn, void *buffer, uint16_t len)
	This function receives a message. More...
int	busart_if_rx_char (uint8_t chn)
	Get byte from USART. More...
uint16_t	busart_if_tx_char (uint8_t chn, char data)
	Sent byte to USART. More...
uint16_t	busart_if_write (uint8_t chn, const void *buffer, uint16_t len)
	This function transmits a message. More...

Variables
static uint8_t	busart_chn_open [2]

#define FREQ_TIMER_POLL_USART   100

#define SERIAL_USART_0   0

#define SERIAL_USART_1   1

#define TIMER_USART_PRIO   10

#define USART0_PRIO   10

Referenced by busart_if_open().

#define USART1_PRIO   10

Referenced by busart_if_open().

#define USART_BUFFER_SIZE   1024

Referenced by busart_if_open().

int8_t busart_if_close

(

uint8_t

chn

)

This function closes and disables communication in the specified USART.

Parameters

chn	Communication channel [0, 1]

Return values

true	on success.
false	on failure.

References tc_stop(), usart_disable_interrupt(), usart_disable_rx(), and usart_disable_tx().

int8_t busart_if_open	(	uint8_t	chn,
		uint32_t	bauds
	)

This function opens an USART.

Note

Opening of the specified USART implies initializing local variables and opening required hardware with the following configuration:

• bauds as specified
• 8 bits, no parity, 1 stop bit
• enable interrupts

Parameters

chn	Communication channel [0, 1]
bauds	Communication speed in bauds

Return values

true	on success.
false	on failure.

References sam_usart_opt_t::baudrate, sam_usart_opt_t::channel_mode, sam_usart_opt_t::char_length, NULL, sam_usart_opt_t::parity_type, pdc_enable_transfer(), pdc_rx_init(), pdc_tx_init(), pmc_enable_periph_clk(), busart_comm_data_t::puc_rq_buf, busart_comm_data_t::puc_tq_buf, sam_usart_opt_t::stop_bits, sysclk_get_peripheral_hz(), tc_start(), pdc_packet::ul_addr, pdc_packet::ul_size, UNUSED, busart_comm_data_t::us_rq_count, busart_comm_data_t::us_rq_idx, busart_comm_data_t::us_wq_idx, USART0_PRIO, USART1_PRIO, USART_BUFFER_SIZE, usart_disable_interrupt(), usart_enable_interrupt(), usart_enable_rx(), usart_enable_tx(), usart_get_pdc_base(), and usart_init_rs232().

Referenced by usi_init().

uint16_t busart_if_read	(	uint8_t	chn,
		void *	buffer,
		uint16_t	len
	)

This function receives a message.

Note

This function receives a given number of characters from the specified USART. If so configured, the function waits until all characters are received. In this case, the watchdog timer must be reloaded to avoid a program reset.

Parameters

chn	Communication channel [0, 1]
buffer	Pointer to buffer for information
len	Number of characters to receive

Return values

Number

of received characters

References busart_comm_data_t::puc_rq_buf, UNUSED, busart_comm_data_t::us_rq_count, and busart_comm_data_t::us_rq_idx.

Referenced by busart_if_rx_char(), and usi_process().

int busart_if_rx_char

(

uint8_t

chn

)

Get byte from USART.

Parameters

chn	Communication channel [0, 1]

Return values

Byte	received
-1	in case of no reception

References busart_if_read().

uint16_t busart_if_tx_char	(	uint8_t	chn,
		char	data
	)

Sent byte to USART.

Parameters

chn	Communication channel [0, 1]
data	Data to sent

Return values

Number

of characters sent

References busart_if_write().

uint16_t busart_if_write	(	uint8_t	chn,
		const void *	buffer,
		uint16_t	len
	)

This function transmits a message.

Note

This function transmits characters via the specified USART. If so configured, the function waits until all characters are inserted in the transmission queue. In this case, the watchdog timer must be reloaded to avoid a program reset.

Parameters

chn	Communication channel [0, 1]
buffer	Pointer to information to transmit
len	Number of characters to transmit

Return values

Number

of characters sent

References NULL, pdc_read_tx_counter(), pdc_tx_init(), busart_comm_data_t::puc_tq_buf, pdc_packet::ul_addr, pdc_packet::ul_size, and UNUSED.

Referenced by _usi_encode_and_send(), and busart_if_tx_char().

uint8_t busart_chn_open[2]

static

Initial value:

= {
    false,
    false
}