source: arduino-1-6-7/trunk/fuentes/arduino-ide-amd64/hardware/arduino/avr/cores/arduino/HardwareSerial_private.h @ 4837

Last change on this file since 4837 was 4837, checked in by daduve, 2 years ago

Adding new version

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1/*
2  HardwareSerial_private.h - Hardware serial library for Wiring
3  Copyright (c) 2006 Nicholas Zambetti.  All right reserved.
4
5  This library is free software; you can redistribute it and/or
6  modify it under the terms of the GNU Lesser General Public
7  License as published by the Free Software Foundation; either
8  version 2.1 of the License, or (at your option) any later version.
9
10  This library is distributed in the hope that it will be useful,
11  but WITHOUT ANY WARRANTY; without even the implied warranty of
12  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  Lesser General Public License for more details.
14
15  You should have received a copy of the GNU Lesser General Public
16  License along with this library; if not, write to the Free Software
17  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
18
19  Modified 23 November 2006 by David A. Mellis
20  Modified 28 September 2010 by Mark Sproul
21  Modified 14 August 2012 by Alarus
22*/
23
24#include "wiring_private.h"
25
26// this next line disables the entire HardwareSerial.cpp,
27// this is so I can support Attiny series and any other chip without a uart
28#if defined(HAVE_HWSERIAL0) || defined(HAVE_HWSERIAL1) || defined(HAVE_HWSERIAL2) || defined(HAVE_HWSERIAL3)
29
30// Ensure that the various bit positions we use are available with a 0
31// postfix, so we can always use the values for UART0 for all UARTs. The
32// alternative, passing the various values for each UART to the
33// HardwareSerial constructor also works, but makes the code bigger and
34// slower.
35#if !defined(TXC0)
36#if defined(TXC)
37// Some chips like ATmega8 don't have UPE, only PE. The other bits are
38// named as expected.
39#if !defined(UPE) && defined(PE)
40#define UPE PE
41#endif
42// On ATmega8, the uart and its bits are not numbered, so there is no TXC0 etc.
43#define TXC0 TXC
44#define RXEN0 RXEN
45#define TXEN0 TXEN
46#define RXCIE0 RXCIE
47#define UDRIE0 UDRIE
48#define U2X0 U2X
49#define UPE0 UPE
50#define UDRE0 UDRE
51#elif defined(TXC1)
52// Some devices have uart1 but no uart0
53#define TXC0 TXC1
54#define RXEN0 RXEN1
55#define TXEN0 TXEN1
56#define RXCIE0 RXCIE1
57#define UDRIE0 UDRIE1
58#define U2X0 U2X1
59#define UPE0 UPE1
60#define UDRE0 UDRE1
61#else
62#error No UART found in HardwareSerial.cpp
63#endif
64#endif // !defined TXC0
65
66// Check at compiletime that it is really ok to use the bit positions of
67// UART0 for the other UARTs as well, in case these values ever get
68// changed for future hardware.
69#if defined(TXC1) && (TXC1 != TXC0 || RXEN1 != RXEN0 || RXCIE1 != RXCIE0 || \
70                      UDRIE1 != UDRIE0 || U2X1 != U2X0 || UPE1 != UPE0 || \
71                      UDRE1 != UDRE0)
72#error "Not all bit positions for UART1 are the same as for UART0"
73#endif
74#if defined(TXC2) && (TXC2 != TXC0 || RXEN2 != RXEN0 || RXCIE2 != RXCIE0 || \
75                      UDRIE2 != UDRIE0 || U2X2 != U2X0 || UPE2 != UPE0 || \
76                      UDRE2 != UDRE0)
77#error "Not all bit positions for UART2 are the same as for UART0"
78#endif
79#if defined(TXC3) && (TXC3 != TXC0 || RXEN3 != RXEN0 || RXCIE3 != RXCIE0 || \
80                      UDRIE3 != UDRIE0 || U3X3 != U3X0 || UPE3 != UPE0 || \
81                      UDRE3 != UDRE0)
82#error "Not all bit positions for UART3 are the same as for UART0"
83#endif
84
85// Constructors ////////////////////////////////////////////////////////////////
86
87HardwareSerial::HardwareSerial(
88  volatile uint8_t *ubrrh, volatile uint8_t *ubrrl,
89  volatile uint8_t *ucsra, volatile uint8_t *ucsrb,
90  volatile uint8_t *ucsrc, volatile uint8_t *udr) :
91    _ubrrh(ubrrh), _ubrrl(ubrrl),
92    _ucsra(ucsra), _ucsrb(ucsrb), _ucsrc(ucsrc),
93    _udr(udr),
94    _rx_buffer_head(0), _rx_buffer_tail(0),
95    _tx_buffer_head(0), _tx_buffer_tail(0)
96{
97}
98
99// Actual interrupt handlers //////////////////////////////////////////////////////////////
100
101void HardwareSerial::_rx_complete_irq(void)
102{
103  if (bit_is_clear(*_ucsra, UPE0)) {
104    // No Parity error, read byte and store it in the buffer if there is
105    // room
106    unsigned char c = *_udr;
107    rx_buffer_index_t i = (unsigned int)(_rx_buffer_head + 1) % SERIAL_RX_BUFFER_SIZE;
108
109    // if we should be storing the received character into the location
110    // just before the tail (meaning that the head would advance to the
111    // current location of the tail), we're about to overflow the buffer
112    // and so we don't write the character or advance the head.
113    if (i != _rx_buffer_tail) {
114      _rx_buffer[_rx_buffer_head] = c;
115      _rx_buffer_head = i;
116    }
117  } else {
118    // Parity error, read byte but discard it
119    *_udr;
120  };
121}
122
123#endif // whole file
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