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9-bit frame support to Hardware Serial 1.0.X #2292

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192 changes: 163 additions & 29 deletions hardware/arduino/cores/arduino/HardwareSerial.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -19,6 +19,7 @@
Modified 23 November 2006 by David A. Mellis
Modified 28 September 2010 by Mark Sproul
Modified 14 August 2012 by Alarus
Modified 12 April 2014 by Bouni
*/

#include <stdlib.h>
Expand Down Expand Up @@ -121,14 +122,26 @@ inline void store_char(unsigned char c, ring_buffer *buffer)
{
#if defined(UDR0)
if (bit_is_clear(UCSR0A, UPE0)) {
unsigned char c = UDR0;
unsigned char c;
// if 9 bit mode, read the ninth bit
if(bit_is_set(UCSR0B, UCSZ02)) {
c = (UCSR0B >> TXB80) & 0x01;
store_char(c, &rx_buffer);
}
c = UDR0;
store_char(c, &rx_buffer);
} else {
unsigned char c = UDR0;
};
#elif defined(UDR)
if (bit_is_clear(UCSRA, PE)) {
unsigned char c = UDR;
unsigned char c;
// if 9 bit mode, read the ninth bit
if(bit_is_set(UCSRB, UCSZ2)) {
c = (UCSRB >> TXB8) & 0x01;
store_char(c, &rx_buffer);
}
c = UDR;
store_char(c, &rx_buffer);
} else {
unsigned char c = UDR;
Expand All @@ -147,7 +160,13 @@ inline void store_char(unsigned char c, ring_buffer *buffer)
ISR(USART1_RX_vect)
{
if (bit_is_clear(UCSR1A, UPE1)) {
unsigned char c = UDR1;
unsigned char c;
// if 9 bit mode, read the ninth bit
if(bit_is_set(UCSR1B, UCSZ12)) {
c = (UCSR1B >> TXB81) & 0x01;
store_char(c, &rx_buffer1);
}
c = UDR1;
store_char(c, &rx_buffer1);
} else {
unsigned char c = UDR1;
Expand All @@ -162,7 +181,13 @@ inline void store_char(unsigned char c, ring_buffer *buffer)
ISR(USART2_RX_vect)
{
if (bit_is_clear(UCSR2A, UPE2)) {
unsigned char c = UDR2;
unsigned char c;
// if 9 bit mode, read the ninth bit
if(bit_is_set(UCSR2B, UCSZ22)) {
c = (UCSR2B >> TXB82) & 0x01;
store_char(c, &rx_buffer2);
}
c = UDR2;
store_char(c, &rx_buffer2);
} else {
unsigned char c = UDR2;
Expand All @@ -177,7 +202,13 @@ inline void store_char(unsigned char c, ring_buffer *buffer)
ISR(USART3_RX_vect)
{
if (bit_is_clear(UCSR3A, UPE3)) {
unsigned char c = UDR3;
unsigned char c;
// if 9 bit mode, read the ninth bit
if(bit_is_set(UCSR3B, UCSZ32)) {
c = (UCSR3B >> TXB83) & 0x01;
store_char(c, &rx_buffer3);
}
c = UDR3;
store_char(c, &rx_buffer3);
} else {
unsigned char c = UDR3;
Expand Down Expand Up @@ -228,13 +259,40 @@ ISR(USART_UDRE_vect)
}
else {
// There is more data in the output buffer. Send the next byte
unsigned char c = tx_buffer.buffer[tx_buffer.tail];
unsigned char c;
#if defined(UCSR0B)
if(bit_is_set(UCSR0B, UCSZ02)) {
// if 9 bit mode, read a byte containing the 9th bit from the buffer
// and write it to the TXB8 in UCSRB
c = tx_buffer.buffer[tx_buffer.tail];
tx_buffer.tail = (tx_buffer.tail + 1) % SERIAL_BUFFER_SIZE;
if(c & 0x01) {
sbi(UCSR0B, TXB80);
} else {
cbi(UCSR0B, TXB80);
}
}
#else
if(bit_is_set(UCSRB, UCSZ2)) {
// if 9 bit mode, read a byte containing the 9th bit from the buffer
// and write it to the TXB8 in UCSRB
c = tx_buffer.buffer[tx_buffer.tail];
tx_buffer.tail = (tx_buffer.tail + 1) % SERIAL_BUFFER_SIZE;
if(c & 0x01) {
sbi(UCSRB, TXB8);
} else {
cbi(UCSRB, TXB8);
}
}
#endif
// read a byte from the buffer and write it to UDR
c = tx_buffer.buffer[tx_buffer.tail];
tx_buffer.tail = (tx_buffer.tail + 1) % SERIAL_BUFFER_SIZE;

#if defined(UDR0)
UDR0 = c;
#elif defined(UDR)
UDR = c;
//UDR = c;
#else
#error UDR not defined
#endif
Expand All @@ -252,7 +310,20 @@ ISR(USART1_UDRE_vect)
}
else {
// There is more data in the output buffer. Send the next byte
unsigned char c = tx_buffer1.buffer[tx_buffer1.tail];
unsigned char c;
if(bit_is_set(UCSR1B, UCSZ12)) {
// if 9 bit mode, read a byte containing the 9th bit from the buffer
// and write it to the TXB8 in UCSRB
c = tx_buffer1.buffer[tx_buffer1.tail];
tx_buffer1.tail = (tx_buffer1.tail + 1) % SERIAL_BUFFER_SIZE;
if(c & 0x01) {
sbi(UCSR1B, TXB81);
} else {
cbi(UCSR1B, TXB81);
}
}
// read a byte from the buffer and write it to UDR
c = tx_buffer1.buffer[tx_buffer1.tail];
tx_buffer1.tail = (tx_buffer1.tail + 1) % SERIAL_BUFFER_SIZE;

UDR1 = c;
Expand All @@ -269,7 +340,20 @@ ISR(USART2_UDRE_vect)
}
else {
// There is more data in the output buffer. Send the next byte
unsigned char c = tx_buffer2.buffer[tx_buffer2.tail];
unsigned char c;
if(bit_is_set(UCSR2B, UCSZ22)) {
// if 9 bit mode, read a byte containing the 9th bit from the buffer
// and write it to the TXB8 in UCSRB
c = tx_buffer2.buffer[tx_buffer2.tail];
tx_buffer2.tail = (tx_buffer2.tail + 1) % SERIAL_BUFFER_SIZE;
if(c & 0x01) {
sbi(UCSR2B, TXB82);
} else {
cbi(UCSR2B, TXB82);
}
}
// read a byte from the buffer and write it to UDR
c = tx_buffer2.buffer[tx_buffer2.tail];
tx_buffer2.tail = (tx_buffer2.tail + 1) % SERIAL_BUFFER_SIZE;

UDR2 = c;
Expand All @@ -286,7 +370,20 @@ ISR(USART3_UDRE_vect)
}
else {
// There is more data in the output buffer. Send the next byte
unsigned char c = tx_buffer3.buffer[tx_buffer3.tail];
unsigned char c;
if(bit_is_set(UCSR2B, UCSZ22)) {
// if 9 bit mode, read a byte containing the 9th bit from the buffer
// and write it to the TXB8 in UCSRB
c = tx_buffer3.buffer[tx_buffer3.tail];
tx_buffer3.tail = (tx_buffer3.tail + 1) % SERIAL_BUFFER_SIZE;
if(c & 0x01) {
sbi(UCSR3B, TXB83);
} else {
cbi(UCSR3B, TXB83);
}
}
// read a byte from the buffer and write it to UDR
c = tx_buffer3.buffer[tx_buffer3.tail];
tx_buffer3.tail = (tx_buffer3.tail + 1) % SERIAL_BUFFER_SIZE;

UDR3 = c;
Expand All @@ -301,7 +398,7 @@ HardwareSerial::HardwareSerial(ring_buffer *rx_buffer, ring_buffer *tx_buffer,
volatile uint8_t *ubrrh, volatile uint8_t *ubrrl,
volatile uint8_t *ucsra, volatile uint8_t *ucsrb,
volatile uint8_t *ucsrc, volatile uint8_t *udr,
uint8_t rxen, uint8_t txen, uint8_t rxcie, uint8_t udrie, uint8_t u2x)
uint8_t ucsz2, uint8_t rxen, uint8_t txen, uint8_t rxcie, uint8_t udrie, uint8_t u2x)
{
_rx_buffer = rx_buffer;
_tx_buffer = tx_buffer;
Expand All @@ -311,6 +408,7 @@ HardwareSerial::HardwareSerial(ring_buffer *rx_buffer, ring_buffer *tx_buffer,
_ucsrb = ucsrb;
_ucsrc = ucsrc;
_udr = udr;
_ucsz2 = ucsz2;
_rxen = rxen;
_txen = txen;
_rxcie = rxcie;
Expand Down Expand Up @@ -362,10 +460,9 @@ void HardwareSerial::begin(unsigned long baud)
cbi(*_ucsrb, _udrie);
}

void HardwareSerial::begin(unsigned long baud, byte config)
void HardwareSerial::begin(unsigned long baud, unsigned int config)
{
uint16_t baud_setting;
uint8_t current_config;
bool use_u2x = true;

#if F_CPU == 16000000UL
Expand Down Expand Up @@ -401,7 +498,12 @@ void HardwareSerial::begin(unsigned long baud, byte config)
#if defined(__AVR_ATmega8__)
config |= 0x80; // select UCSRC register (shared with UBRRH)
#endif
*_ucsrc = config;
// if 9 bit mode, set config bit
if(config & 0x100) {
sbi(*_ucsrb, _ucsz2);
}
// set the lower 8 bits of the config
*_ucsrc = (config & 0x0FF);

sbi(*_ucsrb, _rxen);
sbi(*_ucsrb, _txen);
Expand All @@ -426,15 +528,28 @@ void HardwareSerial::end()

int HardwareSerial::available(void)
{
return (int)(SERIAL_BUFFER_SIZE + _rx_buffer->head - _rx_buffer->tail) % SERIAL_BUFFER_SIZE;
unsigned int a = (SERIAL_BUFFER_SIZE + _rx_buffer->head - _rx_buffer->tail) % SERIAL_BUFFER_SIZE;
if(bit_is_set(*_ucsrb, _ucsz2)) {
// return half the buffer size if 9 bit mode because half the bytes contain the 9th bit
return a/2;
} else {
// return the buffer size
return a;
}
}

int HardwareSerial::peek(void)
{
if (_rx_buffer->head == _rx_buffer->tail) {
return -1;
} else {
return _rx_buffer->buffer[_rx_buffer->tail];
if(bit_is_set(*_ucsrb, _ucsz2)) {
// return 2 bytes from buffer merged into an int (9 bit mode)
return (_rx_buffer->buffer[_rx_buffer->tail] << 8) | _rx_buffer->buffer[(_rx_buffer->tail + 1) % SERIAL_BUFFER_SIZE];
} else {
// return a byte from the buffer
return _rx_buffer->buffer[_rx_buffer->tail];
}
}
}

Expand All @@ -444,9 +559,15 @@ int HardwareSerial::read(void)
if (_rx_buffer->head == _rx_buffer->tail) {
return -1;
} else {
unsigned char c = _rx_buffer->buffer[_rx_buffer->tail];
_rx_buffer->tail = (unsigned int)(_rx_buffer->tail + 1) % SERIAL_BUFFER_SIZE;
return c;
if(bit_is_set(*_ucsrb, _ucsz2)) {
unsigned int c = (_rx_buffer->buffer[_rx_buffer->tail] << 8) | _rx_buffer->buffer[(_rx_buffer->tail + 1) % SERIAL_BUFFER_SIZE ];
_rx_buffer->tail = (unsigned int)(_rx_buffer->tail + 2) % SERIAL_BUFFER_SIZE;
return c;
} else {
unsigned char c = _rx_buffer->buffer[_rx_buffer->tail];
_rx_buffer->tail = (unsigned int)(_rx_buffer->tail + 1) % SERIAL_BUFFER_SIZE;
return c;
}
}
}

Expand All @@ -457,18 +578,31 @@ void HardwareSerial::flush()
transmitting = false;
}

size_t HardwareSerial::write(uint8_t c)
size_t HardwareSerial::write(unsigned int c)
{
int i = (_tx_buffer->head + 1) % SERIAL_BUFFER_SIZE;
int i;
// calculate next head position
if(bit_is_set(*_ucsrb, _ucsz2)) {
// 9 bit mode
i = (_tx_buffer->head + 2) % SERIAL_BUFFER_SIZE;
} else {
// 5 - 8 bit mode
i = (_tx_buffer->head + 1) % SERIAL_BUFFER_SIZE;
}

// If the output buffer is full, there's nothing for it other than to
// wait for the interrupt handler to empty it a bit
// ???: return 0 here instead?
while (i == _tx_buffer->tail)
;

_tx_buffer->buffer[_tx_buffer->head] = c;
_tx_buffer->head = i;
// write 9th bit to the buffer
if(bit_is_set(*_ucsrb, _ucsz2)) {
_tx_buffer->buffer[_tx_buffer->head] = (c >> 8) & 0x01;
_tx_buffer->head = (_tx_buffer->head + 1) % SERIAL_BUFFER_SIZE;
}
// write lower 8 bits to the buffer
_tx_buffer->buffer[_tx_buffer->head] = (uint8_t)c;
_tx_buffer->head = (_tx_buffer->head + 1) % SERIAL_BUFFER_SIZE;

sbi(*_ucsrb, _udrie);
// clear the TXC bit -- "can be cleared by writing a one to its bit location"
Expand All @@ -485,23 +619,23 @@ HardwareSerial::operator bool() {
// Preinstantiate Objects //////////////////////////////////////////////////////

#if defined(UBRRH) && defined(UBRRL)
HardwareSerial Serial(&rx_buffer, &tx_buffer, &UBRRH, &UBRRL, &UCSRA, &UCSRB, &UCSRC, &UDR, RXEN, TXEN, RXCIE, UDRIE, U2X);
HardwareSerial Serial(&rx_buffer, &tx_buffer, &UBRRH, &UBRRL, &UCSRA, &UCSRB, &UCSRC, &UDR, UCSZ2, RXEN, TXEN, RXCIE, UDRIE, U2X);
#elif defined(UBRR0H) && defined(UBRR0L)
HardwareSerial Serial(&rx_buffer, &tx_buffer, &UBRR0H, &UBRR0L, &UCSR0A, &UCSR0B, &UCSR0C, &UDR0, RXEN0, TXEN0, RXCIE0, UDRIE0, U2X0);
HardwareSerial Serial(&rx_buffer, &tx_buffer, &UBRR0H, &UBRR0L, &UCSR0A, &UCSR0B, &UCSR0C, &UDR0, UCSZ02, RXEN0, TXEN0, RXCIE0, UDRIE0, U2X0);
#elif defined(USBCON)
// do nothing - Serial object and buffers are initialized in CDC code
#else
#error no serial port defined (port 0)
#endif

#if defined(UBRR1H)
HardwareSerial Serial1(&rx_buffer1, &tx_buffer1, &UBRR1H, &UBRR1L, &UCSR1A, &UCSR1B, &UCSR1C, &UDR1, RXEN1, TXEN1, RXCIE1, UDRIE1, U2X1);
HardwareSerial Serial1(&rx_buffer1, &tx_buffer1, &UBRR1H, &UBRR1L, &UCSR1A, &UCSR1B, &UCSR1C, &UDR1, UCSZ12, RXEN1, TXEN1, RXCIE1, UDRIE1, U2X1);
#endif
#if defined(UBRR2H)
HardwareSerial Serial2(&rx_buffer2, &tx_buffer2, &UBRR2H, &UBRR2L, &UCSR2A, &UCSR2B, &UCSR2C, &UDR2, RXEN2, TXEN2, RXCIE2, UDRIE2, U2X2);
HardwareSerial Serial2(&rx_buffer2, &tx_buffer2, &UBRR2H, &UBRR2L, &UCSR2A, &UCSR2B, &UCSR2C, &UDR2, UCSZ22, RXEN2, TXEN2, RXCIE2, UDRIE2, U2X2);
#endif
#if defined(UBRR3H)
HardwareSerial Serial3(&rx_buffer3, &tx_buffer3, &UBRR3H, &UBRR3L, &UCSR3A, &UCSR3B, &UCSR3C, &UDR3, RXEN3, TXEN3, RXCIE3, UDRIE3, U2X3);
HardwareSerial Serial3(&rx_buffer3, &tx_buffer3, &UBRR3H, &UBRR3L, &UCSR3A, &UCSR3B, &UCSR3C, &UDR3, UCSZ32, RXEN3, TXEN3, RXCIE3, UDRIE3, U2X3);
#endif

#endif // whole file
Expand Down
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