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Diffstat (limited to 'cores/arduino/HardwareSerial_private.h')
| -rw-r--r-- | cores/arduino/HardwareSerial_private.h | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/cores/arduino/HardwareSerial_private.h b/cores/arduino/HardwareSerial_private.h new file mode 100644 index 0000000..761a5e5 --- /dev/null +++ b/cores/arduino/HardwareSerial_private.h @@ -0,0 +1,123 @@ +/* + HardwareSerial_private.h - Hardware serial library for Wiring + Copyright (c) 2006 Nicholas Zambetti. All right reserved. + + 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 2.1 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 library; if not, write to the Free Software + Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + + Modified 23 November 2006 by David A. Mellis + Modified 28 September 2010 by Mark Sproul + Modified 14 August 2012 by Alarus +*/ + +#include "wiring_private.h" + +// this next line disables the entire HardwareSerial.cpp, +// this is so I can support Attiny series and any other chip without a uart +#if defined(HAVE_HWSERIAL0) || defined(HAVE_HWSERIAL1) || defined(HAVE_HWSERIAL2) || defined(HAVE_HWSERIAL3) + +// Ensure that the various bit positions we use are available with a 0 +// postfix, so we can always use the values for UART0 for all UARTs. The +// alternative, passing the various values for each UART to the +// HardwareSerial constructor also works, but makes the code bigger and +// slower. +#if !defined(TXC0) +#if defined(TXC) +// Some chips like ATmega8 don't have UPE, only PE. The other bits are +// named as expected. +#if !defined(UPE) && defined(PE) +#define UPE PE +#endif +// On ATmega8, the uart and its bits are not numbered, so there is no TXC0 etc. +#define TXC0 TXC +#define RXEN0 RXEN +#define TXEN0 TXEN +#define RXCIE0 RXCIE +#define UDRIE0 UDRIE +#define U2X0 U2X +#define UPE0 UPE +#define UDRE0 UDRE +#elif defined(TXC1) +// Some devices have uart1 but no uart0 +#define TXC0 TXC1 +#define RXEN0 RXEN1 +#define TXEN0 TXEN1 +#define RXCIE0 RXCIE1 +#define UDRIE0 UDRIE1 +#define U2X0 U2X1 +#define UPE0 UPE1 +#define UDRE0 UDRE1 +#else +#error No UART found in HardwareSerial.cpp +#endif +#endif // !defined TXC0 + +// Check at compiletime that it is really ok to use the bit positions of +// UART0 for the other UARTs as well, in case these values ever get +// changed for future hardware. +#if defined(TXC1) && (TXC1 != TXC0 || RXEN1 != RXEN0 || RXCIE1 != RXCIE0 || \ + UDRIE1 != UDRIE0 || U2X1 != U2X0 || UPE1 != UPE0 || \ + UDRE1 != UDRE0) +#error "Not all bit positions for UART1 are the same as for UART0" +#endif +#if defined(TXC2) && (TXC2 != TXC0 || RXEN2 != RXEN0 || RXCIE2 != RXCIE0 || \ + UDRIE2 != UDRIE0 || U2X2 != U2X0 || UPE2 != UPE0 || \ + UDRE2 != UDRE0) +#error "Not all bit positions for UART2 are the same as for UART0" +#endif +#if defined(TXC3) && (TXC3 != TXC0 || RXEN3 != RXEN0 || RXCIE3 != RXCIE0 || \ + UDRIE3 != UDRIE0 || U3X3 != U3X0 || UPE3 != UPE0 || \ + UDRE3 != UDRE0) +#error "Not all bit positions for UART3 are the same as for UART0" +#endif + +// Constructors //////////////////////////////////////////////////////////////// + +HardwareSerial::HardwareSerial( + volatile uint8_t *ubrrh, volatile uint8_t *ubrrl, + volatile uint8_t *ucsra, volatile uint8_t *ucsrb, + volatile uint8_t *ucsrc, volatile uint8_t *udr) : + _ubrrh(ubrrh), _ubrrl(ubrrl), + _ucsra(ucsra), _ucsrb(ucsrb), _ucsrc(ucsrc), + _udr(udr), + _rx_buffer_head(0), _rx_buffer_tail(0), + _tx_buffer_head(0), _tx_buffer_tail(0) +{ +} + +// Actual interrupt handlers ////////////////////////////////////////////////////////////// + +void HardwareSerial::_rx_complete_irq(void) +{ + if (bit_is_clear(*_ucsra, UPE0)) { + // No Parity error, read byte and store it in the buffer if there is + // room + unsigned char c = *_udr; + rx_buffer_index_t i = (unsigned int)(_rx_buffer_head + 1) % SERIAL_RX_BUFFER_SIZE; + + // if we should be storing the received character into the location + // just before the tail (meaning that the head would advance to the + // current location of the tail), we're about to overflow the buffer + // and so we don't write the character or advance the head. + if (i != _rx_buffer_tail) { + _rx_buffer[_rx_buffer_head] = c; + _rx_buffer_head = i; + } + } else { + // Parity error, read byte but discard it + *_udr; + }; +} + +#endif // whole file |