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-rw-r--r--cores/arduino/HardwareSerial.cpp110
1 files changed, 93 insertions, 17 deletions
diff --git a/cores/arduino/HardwareSerial.cpp b/cores/arduino/HardwareSerial.cpp
index f40ddee..2e64acb 100644
--- a/cores/arduino/HardwareSerial.cpp
+++ b/cores/arduino/HardwareSerial.cpp
@@ -18,6 +18,7 @@
Modified 23 November 2006 by David A. Mellis
Modified 28 September 2010 by Mark Sproul
+ Modified 14 August 2012 by Alarus
*/
#include <stdlib.h>
@@ -109,13 +110,22 @@ inline void store_char(unsigned char c, ring_buffer *buffer)
#endif
{
#if defined(UDR0)
- unsigned char c = UDR0;
+ if (bit_is_clear(UCSR0A, UPE0)) {
+ unsigned char c = UDR0;
+ store_char(c, &rx_buffer);
+ } else {
+ unsigned char c = UDR0;
+ };
#elif defined(UDR)
- unsigned char c = UDR;
+ if (bit_is_clear(UCSRA, PE)) {
+ unsigned char c = UDR;
+ store_char(c, &rx_buffer);
+ } else {
+ unsigned char c = UDR;
+ };
#else
#error UDR not defined
#endif
- store_char(c, &rx_buffer);
}
#endif
#endif
@@ -126,8 +136,12 @@ inline void store_char(unsigned char c, ring_buffer *buffer)
#define serialEvent1_implemented
SIGNAL(USART1_RX_vect)
{
- unsigned char c = UDR1;
- store_char(c, &rx_buffer1);
+ if (bit_is_clear(UCSR1A, UPE1)) {
+ unsigned char c = UDR1;
+ store_char(c, &rx_buffer1);
+ } else {
+ unsigned char c = UDR1;
+ };
}
#elif defined(SIG_USART1_RECV)
#error SIG_USART1_RECV
@@ -139,8 +153,12 @@ inline void store_char(unsigned char c, ring_buffer *buffer)
#define serialEvent2_implemented
SIGNAL(USART2_RX_vect)
{
- unsigned char c = UDR2;
- store_char(c, &rx_buffer2);
+ if (bit_is_clear(UCSR2A, UPE2)) {
+ unsigned char c = UDR2;
+ store_char(c, &rx_buffer2);
+ } else {
+ unsigned char c = UDR2;
+ };
}
#elif defined(SIG_USART2_RECV)
#error SIG_USART2_RECV
@@ -152,8 +170,12 @@ inline void store_char(unsigned char c, ring_buffer *buffer)
#define serialEvent3_implemented
SIGNAL(USART3_RX_vect)
{
- unsigned char c = UDR3;
- store_char(c, &rx_buffer3);
+ if (bit_is_clear(UCSR3A, UPE3)) {
+ unsigned char c = UDR3;
+ store_char(c, &rx_buffer3);
+ } else {
+ unsigned char c = UDR3;
+ };
}
#elif defined(SIG_USART3_RECV)
#error SIG_USART3_RECV
@@ -274,7 +296,7 @@ ISR(USART3_UDRE_vect)
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 *udr,
+ volatile uint8_t *ucsrc, volatile uint8_t *udr,
uint8_t rxen, uint8_t txen, uint8_t rxcie, uint8_t udrie, uint8_t u2x)
{
_rx_buffer = rx_buffer;
@@ -283,6 +305,7 @@ HardwareSerial::HardwareSerial(ring_buffer *rx_buffer, ring_buffer *tx_buffer,
_ubrrl = ubrrl;
_ucsra = ucsra;
_ucsrb = ucsrb;
+ _ucsrc = ucsrc;
_udr = udr;
_rxen = rxen;
_txen = txen;
@@ -327,6 +350,55 @@ try_again:
*_ubrrh = baud_setting >> 8;
*_ubrrl = baud_setting;
+ transmitting = false;
+
+ sbi(*_ucsrb, _rxen);
+ sbi(*_ucsrb, _txen);
+ sbi(*_ucsrb, _rxcie);
+ cbi(*_ucsrb, _udrie);
+}
+
+void HardwareSerial::begin(unsigned long baud, byte config)
+{
+ uint16_t baud_setting;
+ uint8_t current_config;
+ bool use_u2x = true;
+
+#if F_CPU == 16000000UL
+ // hardcoded exception for compatibility with the bootloader shipped
+ // with the Duemilanove and previous boards and the firmware on the 8U2
+ // on the Uno and Mega 2560.
+ if (baud == 57600) {
+ use_u2x = false;
+ }
+#endif
+
+try_again:
+
+ if (use_u2x) {
+ *_ucsra = 1 << _u2x;
+ baud_setting = (F_CPU / 4 / baud - 1) / 2;
+ } else {
+ *_ucsra = 0;
+ baud_setting = (F_CPU / 8 / baud - 1) / 2;
+ }
+
+ if ((baud_setting > 4095) && use_u2x)
+ {
+ use_u2x = false;
+ goto try_again;
+ }
+
+ // assign the baud_setting, a.k.a. ubbr (USART Baud Rate Register)
+ *_ubrrh = baud_setting >> 8;
+ *_ubrrl = baud_setting;
+
+ //set the data bits, parity, and stop bits
+#if defined(__AVR_ATmega8__)
+ config |= 0x80; // select UCSRC register (shared with UBRRH)
+#endif
+ *_ucsrc = config;
+
sbi(*_ucsrb, _rxen);
sbi(*_ucsrb, _txen);
sbi(*_ucsrb, _rxcie);
@@ -376,8 +448,9 @@ int HardwareSerial::read(void)
void HardwareSerial::flush()
{
- while (_tx_buffer->head != _tx_buffer->tail)
- ;
+ // UDR is kept full while the buffer is not empty, so TXC triggers when EMPTY && SENT
+ while (transmitting && ! (*_ucsra & _BV(TXC0)));
+ transmitting = false;
}
size_t HardwareSerial::write(uint8_t c)
@@ -394,6 +467,9 @@ size_t HardwareSerial::write(uint8_t c)
_tx_buffer->head = i;
sbi(*_ucsrb, _udrie);
+ // clear the TXC bit -- "can be cleared by writing a one to its bit location"
+ transmitting = true;
+ sbi(*_ucsra, TXC0);
return 1;
}
@@ -405,9 +481,9 @@ HardwareSerial::operator bool() {
// Preinstantiate Objects //////////////////////////////////////////////////////
#if defined(UBRRH) && defined(UBRRL)
- HardwareSerial Serial(&rx_buffer, &tx_buffer, &UBRRH, &UBRRL, &UCSRA, &UCSRB, &UDR, RXEN, TXEN, RXCIE, UDRIE, U2X);
+ HardwareSerial Serial(&rx_buffer, &tx_buffer, &UBRRH, &UBRRL, &UCSRA, &UCSRB, &UCSRC, &UDR, RXEN, TXEN, RXCIE, UDRIE, U2X);
#elif defined(UBRR0H) && defined(UBRR0L)
- HardwareSerial Serial(&rx_buffer, &tx_buffer, &UBRR0H, &UBRR0L, &UCSR0A, &UCSR0B, &UDR0, RXEN0, TXEN0, RXCIE0, UDRIE0, U2X0);
+ HardwareSerial Serial(&rx_buffer, &tx_buffer, &UBRR0H, &UBRR0L, &UCSR0A, &UCSR0B, &UCSR0C, &UDR0, RXEN0, TXEN0, RXCIE0, UDRIE0, U2X0);
#elif defined(USBCON)
// do nothing - Serial object and buffers are initialized in CDC code
#else
@@ -415,13 +491,13 @@ HardwareSerial::operator bool() {
#endif
#if defined(UBRR1H)
- HardwareSerial Serial1(&rx_buffer1, &tx_buffer1, &UBRR1H, &UBRR1L, &UCSR1A, &UCSR1B, &UDR1, RXEN1, TXEN1, RXCIE1, UDRIE1, U2X1);
+ HardwareSerial Serial1(&rx_buffer1, &tx_buffer1, &UBRR1H, &UBRR1L, &UCSR1A, &UCSR1B, &UCSR1C, &UDR1, RXEN1, TXEN1, RXCIE1, UDRIE1, U2X1);
#endif
#if defined(UBRR2H)
- HardwareSerial Serial2(&rx_buffer2, &tx_buffer2, &UBRR2H, &UBRR2L, &UCSR2A, &UCSR2B, &UDR2, RXEN2, TXEN2, RXCIE2, UDRIE2, U2X2);
+ HardwareSerial Serial2(&rx_buffer2, &tx_buffer2, &UBRR2H, &UBRR2L, &UCSR2A, &UCSR2B, &UCSR2C, &UDR2, RXEN2, TXEN2, RXCIE2, UDRIE2, U2X2);
#endif
#if defined(UBRR3H)
- HardwareSerial Serial3(&rx_buffer3, &tx_buffer3, &UBRR3H, &UBRR3L, &UCSR3A, &UCSR3B, &UDR3, RXEN3, TXEN3, RXCIE3, UDRIE3, U2X3);
+ HardwareSerial Serial3(&rx_buffer3, &tx_buffer3, &UBRR3H, &UBRR3L, &UCSR3A, &UCSR3B, &UCSR3C, &UDR3, RXEN3, TXEN3, RXCIE3, UDRIE3, U2X3);
#endif
#endif // whole file
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-11-23 01:02:38 +0000