/**************************************************************************//**
* \brief USART0 library
* \author Copyright (C) 2011 Julien Le Sech - www.idreammicro.com
* \version 1.0
* \date 20090426
*
* This file is part of the iDreamMicro library.
*
* This library is free software: you can redistribute it and/or modify it under
* the terms of the GNU Lesser General Public License as published by the Free
* Software Foundation, either version 3 of the License, or (at your option) any
* later version.
*
* This library is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
* details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see http://www.gnu.org/licenses/
******************************************************************************/
/**************************************************************************//**
* \file usart0_m328.c
******************************************************************************/
/******************************************************************************
* Header file inclusions.
******************************************************************************/
#include "../usart0.h"
#include <usart/usart.h>
#include <useful/bits.h>
#include <avr/interrupt.h>
#include <avr/io.h>
#include <assert.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>
/******************************************************************************
* Private variable declarations.
******************************************************************************/
static usart__rx_complete_callback_t
* p_rx_complete
= NULL
;
static usart__tx_complete_callback_t
* p_tx_complete
= NULL
;
static usart__data_register_empty_callback_t
* p_data_register_empty
= NULL
;
static usart__configuration_t configuration
=
{
.
mode = USART__MODE__ASYNCHRONOUS
,
.
baudrate = USART__BAUDRATE__9600
,
.
data_size = USART__DATA_SIZE__8_BITS
,
.
stop_size = USART__STOP_SIZE__1_BIT
,
.
parity = USART__PARITY__DISABLED
};
static bool double_speed_is_set
= false;
/******************************************************************************
* Private function prototypes.
******************************************************************************/
/**************************************************************************//**
* \fn static inline uint16_t usart0__compute_ubrr(void)
*
* \brief Compute UBRR register value.
*
* \return UBRR value.
******************************************************************************/
static inline
uint16_t
usart0__compute_ubrr
(
void
);
/******************************************************************************
* Public function definitions.
******************************************************************************/
/**************************************************************************//**
* \fn void usart0__initialize(usart__configuration_t* p_configuration)
*
* \brief Initialize USART0.
*
* \param[in] p_configuration USART configuration. If null, default settings
* will be used.
*
* Default settings:
* - baudrate = 9600 bps;
* - 8 data bits;
* - 1 stop bit;
* - no parity.
******************************************************************************/
void
usart0__initialize
(
usart__configuration_t
* p_configuration
){
// If p_configuration is not null, use it!
if (NULL
!= p_configuration
)
{
configuration
= *p_configuration
;
}
// Set mode.
usart0__set_mode
(configuration.
mode);
// Set baud rate.
usart0__set_baudrate
(configuration.
baudrate);
usart0__set_double_speed
(false);
// Configure settings.
usart0__set_data_size
(configuration.
data_size);
usart0__set_stop_size
(configuration.
stop_size);
usart0__set_parity
(configuration.
parity);
}
/**************************************************************************//**
* \fn void usart0__set_baudrate(usart__baudrate_t baudrate)
*
* \brief Set USART0 baudrate.
*
* \param baudrate baudrate to set (in bauds per second)
******************************************************************************/
void
usart0__set_baudrate
(
usart__baudrate_t baudrate
){
configuration.
baudrate = baudrate
;
uint16_t ubrr
= usart0__compute_ubrr
();
UBRR0H
= (uint8_t)(ubrr
>> 8);
UBRR0L
= (uint8_t)ubrr
;
}
/**************************************************************************//**
* \fn void usart0__set_mode(usart__mode_t usart_mode)
*
* \brief Set USART0 mode.
*
* \param usart_mode Mode to set.
******************************************************************************/
void
usart0__set_mode
(
usart__mode_t usart_mode
){
// Check the preconditions.
assert(USART__MODE__INVALID
> usart_mode
);
configuration.
mode = usart_mode
;
switch (usart_mode
)
{
case USART__MODE__ASYNCHRONOUS
:
{
BIT__RST
(UCSR0C
, UMSEL01
);
BIT__RST
(UCSR0C
, UMSEL00
);
}
break;
case USART__MODE__SYNCHRONOUS
:
{
BIT__RST
(UCSR0C
, UMSEL01
);
BIT__SET
(UCSR0C
, UMSEL00
);
}
break;
case USART__MODE__MASTER_SPI
:
{
BIT__SET
(UCSR0C
, UMSEL01
);
BIT__SET
(UCSR0C
, UMSEL00
);
}
break;
case USART__MODE__INVALID
:
default:
break;
}
}
/**************************************************************************//**
* \fn void usart0__set_data_size(usart__data_sizet data_size)
*
* \brief Set USART0 data size.
*
* \param data_size data size (in bits)
******************************************************************************/
void
usart0__set_data_size
(
usart__data_size_t data_size
){
configuration.
data_size = data_size
;
switch (data_size
)
{
case USART__DATA_SIZE__5_BITS
:
{
BIT__RST
(UCSR0B
, UCSZ02
);
BIT__RST
(UCSR0C
, UCSZ01
);
BIT__RST
(UCSR0C
, UCSZ00
);
}
break;
case USART__DATA_SIZE__6_BITS
:
{
BIT__RST
(UCSR0B
, UCSZ02
);
BIT__RST
(UCSR0C
, UCSZ01
);
BIT__SET
(UCSR0C
, UCSZ00
);
}
break;
case USART__DATA_SIZE__7_BITS
:
{
BIT__RST
(UCSR0B
, UCSZ02
);
BIT__SET
(UCSR0C
, UCSZ01
);
BIT__RST
(UCSR0C
, UCSZ00
);
}
break;
case USART__DATA_SIZE__8_BITS
:
{
BIT__RST
(UCSR0B
, UCSZ02
);
BIT__SET
(UCSR0C
, UCSZ01
);
BIT__SET
(UCSR0C
, UCSZ00
);
}
break;
case USART__DATA_SIZE__9_BITS
:
{
BIT__SET
(UCSR0B
, UCSZ02
);
BIT__SET
(UCSR0C
, UCSZ01
);
BIT__SET
(UCSR0C
, UCSZ00
);
}
break;
default:
break;
}
}
/**************************************************************************//**
* \fn void usart0__set_stop_size(usart__stop_size_t stop_size)
*
* \brief Set USART0 stop size.
*
* \param stop_size stop size (in bits)
******************************************************************************/
void
usart0__set_stop_size
(
usart__stop_size_t stop_size
){
configuration.
stop_size = stop_size
;
if (USART__STOP_SIZE__1_BIT
== stop_size
)
{
BIT__RST
(UCSR0C
, USBS0
);
}
else
{
BIT__SET
(UCSR0C
, USBS0
);
}
}
/**************************************************************************//**
* \fn void usart0__set_parity(usart__parity_t parity)
*
* \brief Set USART0 parity.
*
* \param parity parity to set
******************************************************************************/
void
usart0__set_parity
(
usart__parity_t parity
){
configuration.
parity = parity
;
switch (parity
)
{
case USART__PARITY__DISABLED
:
{
BIT__RST
(UCSR0C
, UPM01
);
BIT__RST
(UCSR0C
, UPM00
);
}
break;
case USART__PARITY__EVEN
:
{
BIT__SET
(UCSR0C
, UPM01
);
BIT__RST
(UCSR0C
, UPM00
);
}
break;
case USART__PARITY__ODD
:
{
BIT__SET
(UCSR0C
, UPM01
);
BIT__SET
(UCSR0C
, UPM00
);
}
break;
default:
break;
}
}
/**************************************************************************//**
* \fn void usart0__set_double_speed(bool double_speed)
*
* \brief Set double speed.
*
* \param double_speed True to set double speed, false otherwise.
******************************************************************************/
void
usart0__set_double_speed
(
bool double_speed
){
double_speed_is_set
= double_speed
;
if (double_speed_is_set
)
{
BIT__SET
(UCSR0A
, U2X0
);
}
else
{
BIT__RST
(UCSR0A
, U2X0
);
}
}
/**************************************************************************//**
* \fn void usart0__enable_receiver(void)
*
* \brief Enable USART 0 receiver.
******************************************************************************/
void
usart0__enable_receiver
(
void
){
BIT__SET
(UCSR0B
, RXEN0
);
}
/**************************************************************************//**
* \fn void usart0__disable_receiver(void)
*
* \brief Disable USART 0 receiver.
******************************************************************************/
void
usart0__disable_receiver
(
void
){
BIT__RST
(UCSR0B
, RXEN0
);
}
/**************************************************************************//**
* \fn void usart0__enable_transmitter(void)
*
* \brief Enable USART 0 transmitter.
******************************************************************************/
void
usart0__enable_transmitter
(
void
){
BIT__SET
(UCSR0B
, TXEN0
);
}
/**************************************************************************//**
* \fn void usart0__disable_transmitter(void)
*
* \brief Disable USART 0 transmitter.
******************************************************************************/
void
usart0__disable_transmitter
(
void
){
BIT__RST
(UCSR0B
, TXEN0
);
}
/**************************************************************************//**
* \fn uint8_t usart0__receive_byte(void)
*
* \brief Receive a byte on USART0.
*
* \return received byte
******************************************************************************/
uint16_t
usart0__receive_byte
(
void
){
// Wait for data to be received.
while (!(UCSR0A
& (1 << RXC0
)));
// Get received data.
uint16_t received_byte
= UDR0
;
if (USART__DATA_SIZE__9_BITS
== configuration.
data_size)
{
// If 9-bit data size, get 9th bit.
uint8_t resh
= UCSR0B
;
resh
= (resh
>> 1) & 0x01;
received_byte
= (resh
<< 8) | received_byte
;
}
// Return received data from buffer.
return received_byte
;
}
/**************************************************************************//**
* \fn usart0__transmit_byte(uint8_t byte_to_transmit)
*
* \brief Transmit a byte on USART0.
*
* \param byte_to_transmit byte to transmit
******************************************************************************/
void
usart0__transmit_byte
(
uint16_t byte_to_transmit
){
// Wait for empty transmit buffer.
while (!(UCSR0A
& (1 << UDRE0
)));
if (USART__DATA_SIZE__9_BITS
== configuration.
data_size)
{
// If 9-bit data size, copy 9th bit to TXB80.
UCSR0B
&= ~
(1 << TXB80
);
if (byte_to_transmit
& 0x0100)
{
UCSR0B
|= (1 << TXB80
);
}
}
// Put data into transmit buffer, sends the data.
UDR0
= byte_to_transmit
;
}
/**************************************************************************//**
* \fn void usart0__flush(void)
*
* \brief Flush USART0 receiver buffer.
******************************************************************************/
void
usart0__flush
(
void
){
uint8_t dummy
= 0;
while (UCSR0A
& (1 << RXC0
))
{
dummy
= UDR0
;
}
}
/**************************************************************************//**
* \fn void usart0__enable_rx_complete_interrupt(void)
*
* \brief Enable USART 0 receive complete interrupt.
******************************************************************************/
void
usart0__enable_rx_complete_interrupt
(
void
){
BIT__SET
(UCSR0B
, RXCIE0
);
sei
();
}
/**************************************************************************//**
* \fn void usart0__disable_rx_complete_interrupt(void)
*
* \brief Disable USART 0 receive complete interrupt.
******************************************************************************/
void
usart0__disable_rx_complete_interrupt
(
void
){
BIT__RST
(UCSR0B
, RXCIE0
);
sei
();
}
/**************************************************************************//**
* \fn void usart0__set_rx_complete_callback(
* const usart__rx_complete_callback_t* p_callback)
*
* \brief Set a callback to call when receive byte complete interrupt is
* generated.
*
* \param[in] p_callback Callback to set.
******************************************************************************/
void
usart0__set_rx_complete_callback
(
const usart__rx_complete_callback_t
* p_callback
){
// Check the preconditions.
assert(NULL
!= p_callback
);
p_rx_complete
= p_callback
;
}
/**************************************************************************//**
* \fn void usart0__enable_tx_complete_interrupt(void)
*
* \brief Enable interrupt when TX complete.
******************************************************************************/
void
usart0__enable_tx_complete_interrupt
(
void
){
BIT__SET
(UCSR0B
, TXCIE0
);
sei
();
}
/**************************************************************************//**
* \fn void usart0__disable_tx_complete_interrupt(void)
*
* \brief Disable interrupt when TX complete.
******************************************************************************/
void
usart0__disable_tx_complete_interrupt
(
void
){
BIT__RST
(UCSR0B
, TXCIE0
);
sei
();
}
/**************************************************************************//**
* \fn void usart0__set_tx_complete_callback(
* const usart__tx_complete_callback_t* p_callback)
*
* \brief Set a callback to call when TX is complete.
*
* \param[in] p_callback Function to call.
******************************************************************************/
void
usart0__set_tx_complete_callback
(
const usart__tx_complete_callback_t
* p_callback
){
// Check the preconditions.
assert(NULL
!= p_callback
);
p_tx_complete
= p_callback
;
}
/**************************************************************************//**
* \fn void usart0__enable_data_register_empty_interrupt()
*
* \brief Enable interrupt when data register is empty.
******************************************************************************/
void
usart0__enable_data_register_empty_interrupt
(
void
){
BIT__SET
(UCSR0B
, UDRIE0
);
sei
();
}
/**************************************************************************//**
* \fn void usart0__disable_data_register_empty_interrupt()
*
* \brief Disable interrupt when data register is empty.
******************************************************************************/
void
usart0__disable_data_register_empty_interrupt
(
void
){
BIT__RST
(UCSR0B
, UDRIE0
);
sei
();
}
/**************************************************************************//**
* \fn void usart0__set_data_register_empty_callback(
* const usart__data_register_empty_callback_t* p_callback)
*
* \brief Set a callback to call when data register is empty.
*
* \param[in] p_callback Function to call.
******************************************************************************/
void
usart0__set_data_register_empty_callback
(
const usart__data_register_empty_callback_t
* p_callback
){
// Check the preconditions.
assert(NULL
!= p_callback
);
p_data_register_empty
= p_callback
;
}
/******************************************************************************
* Private function definitions.
******************************************************************************/
/**************************************************************************//**
* \fn static inline uint16_t usart0__compute_ubrr(void)
*
* \brief Compute UBRR register value.
*
* \return UBRR value.
******************************************************************************/
static inline
uint16_t
usart0__compute_ubrr
(
void
){
uint16_t ubrr
= 0;
switch (configuration.
mode)
{
case USART__MODE__ASYNCHRONOUS
:
{
if (!double_speed_is_set
)
{
ubrr
= F_CPU
/ (16 * configuration.
baudrate) - 1;
}
else
{
ubrr
= F_CPU
/ (8 * configuration.
baudrate) - 1;
}
}
break;
case USART__MODE__SYNCHRONOUS
:
{
ubrr
= F_CPU
/ (2 * configuration.
baudrate) - 1;
}
break;
case USART__MODE__MASTER_SPI
:
break;
default:
break;
}
return ubrr
;
}
/******************************************************************************
* Interrupt vectors.
******************************************************************************/
/**************************************************************************//**
* \fn ISR(USART_RX_vect)
*
* \brief RX interrupt vector.
******************************************************************************/
ISR
(USART_RX_vect
)
{
if (NULL
!= p_rx_complete
)
{
p_rx_complete
();
}
}
/**************************************************************************//**
* \fn ISR(USART_TX_vect)
*
* \brief TX interrupt vector.
******************************************************************************/
ISR
(USART_TX_vect
)
{
if (NULL
!= p_tx_complete
)
{
p_tx_complete
();
}
}
/**************************************************************************//**
* \fn ISR(USART_UDRE_vect)
*
* \brief Data register empty interrupt vector.
******************************************************************************/
ISR
(USART_UDRE_vect
)
{
if (NULL
!= p_data_register_empty
)
{
p_data_register_empty
();
}
}