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authorCristian Maglie <c.maglie@bug.st>2014-01-27 22:48:17 +0100
committerCristian Maglie <c.maglie@bug.st>2014-01-27 22:48:17 +0100
commite088421ef902180f6561f906181408133796531f (patch)
tree88a5b32b3cf2588bb6a2a442b417489b72e5bae0 /cores/arduino/HardwareSerial_private.h
parentf01025a70d6c11c09e32033195f4a9396462fb05 (diff)
parentc3cd35f1979290d072ab77a6805dc4419f2ef6fb (diff)
Merge branch 'serial-patch-2' into ide-1.5.x
Diffstat (limited to 'cores/arduino/HardwareSerial_private.h')
-rw-r--r--cores/arduino/HardwareSerial_private.h95
1 files changed, 95 insertions, 0 deletions
diff --git a/cores/arduino/HardwareSerial_private.h b/cores/arduino/HardwareSerial_private.h
new file mode 100644
index 0000000..54a0c7a
--- /dev/null
+++ b/cores/arduino/HardwareSerial_private.h
@@ -0,0 +1,95 @@
+#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)
+// 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),
+ _tx_buffer_head(0), _tx_buffer_tail(0),
+ _rx_buffer_head(0), _rx_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;
+ int i = (unsigned int)(_rx_buffer_head + 1) % SERIAL_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
+ unsigned char c = *_udr;
+ };
+}
+
+#endif // whole file