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path: root/cores/arduino/HardwareSerial.cpp
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2014-01-16Move interrupt handlers into HardwareSerial classMatthijs Kooijman
The actual interrupt vectors are of course defined as before, but they let new methods in the HardwareSerial class do the actual work. This greatly reduces code duplication and prepares for one of my next commits which requires the tx interrupt handler to be called from another context as well. The actual content of the interrupts handlers was pretty much identical, so that remains unchanged (except that store_char was now only needed once, so it was inlined). Now all access to the buffers are inside the HardwareSerial class, the buffer variables can be made private. One would expect a program size reduction from this change (at least with multiple UARTs), but due to the fact that the interrupt handlers now only have indirect access to a few registers (which previously were just hardcoded in the handlers) and because there is some extra function call overhead, the code size on the uno actually increases by around 70 bytes. On the mega, which has four UARTs, the code size decreases by around 70 bytes.
2014-01-16Use constants for register bit positions in HardwareSerialMatthijs Kooijman
Previously, the constants to use for the bit positions of the various UARTs were passed to the HardwareSerial constructor. However, this meant that whenever these values were used, the had to be indirectly loaded, resulting in extra code overhead. Additionally, since there is no instruction to shift a value by a variable amount, the 1 << x expressions (inside _BV and sbi() / cbi()) would be compiled as a loop instead of being evaluated at compiletime. Now, the HardwareSerial class always uses the constants for the bit positions of UART 0 (and some code is present to make sure these constants exist, even for targets that only have a single unnumbered UART or start at UART1). This was already done for the TXC0 constant, for some reason. For the actual register addresses, this approach does not work, since these are of course different between the different UARTs on a single chip. Of course, always using the UART 0 constants is only correct when the constants are actually identical for the different UARTs. It has been verified that this is currently the case for all targets supported by avr-gcc 4.7.2, and the code contains compile-time checks to verify this for the current target, in case a new target is added for which this does not hold. This verification was done using: for i in TXC RXEN TXEN RXCIE UDRIE U2X UPE; do echo $i; grep --no-filename -r "#define $i[0-9]\? " /usr/lib/avr/include/avr/io* | sed "s/#define $i[0-9]\?\s*\(\S\)\+\s*\(\/\*.*\*\/\)\?$/\1/" | sort | uniq ; done This command shows that the above constants are identical for all uarts on all platforms, except for TXC, which is sometimes 6 and sometimes 0. Further investigation shows that it is always 6, except in io90scr100.h, but that file defines TXC0 with value 6 for the UART and uses TXC with value 0 for some USB-related register. This commit reduces program size on the uno by around 120 bytes.
2014-01-16Simplify HardwareSerial::begin()Matthijs Kooijman
This simplifies the baud rate calculation, removing the need for a goto and shortening the code a bit. Other than that, this code should not use any different settings than before. Code was suggested by Rob Tillaart on github. Closes: #1262
2014-01-16Remove unused variableMatthijs Kooijman
2014-01-16Slightly reduce code utilization by inlining HardwareSerail begin(baud) and ↵Cristian Maglie
operator bool()
2014-01-16Remove duplicate code from HardwareSerial::begin() methods.Matthijs Kooijman
There are two begin methods, one which accepts just a baud rate and uses the default bit settings and one which accepts both a baudrate and a bit config. Previously, both of these contained a complete implementation, but now the former just calls the latter, explicitely passing the default 8N1 configuration. Technically, this causes a small change: Before the UCSRC register was untouched when calling begin(baud), now it is explicitely initialized with 8N1. However, since this is the default configuration for at least the Uno and the Mega (didn't check any others), probably for all avrs, this shouldn't effectively change anything. Given that the Arduino documentation also documents this as the default when none is passed, explicitly setting it is probably a good idea in any case.
2013-09-09Fixed HardwareSerial bug introduced in 1.5.3.Cristian Maglie
Fixes #1568
2013-07-26Move buffers into HardwareSerialMatthijs Kooijman
This removes the need for doing an extra pointer dereference on every access to the buffers, shrinking the code by around 100 bytes. The members for these buffers must be public for now, since the interrupt handlers also need to access them. These can later be made private again. Furthermore, the struct ring_buffer was removed. This allows the all head and tail pointers to be put into the HardwareSerial struct before the actual buffers, so the pointers all end up in the first 32 bytes of the struct that can be accessed using a single instruction (ldd). References: #947
2013-07-26Use uint8_t for HardwareSerial ringbuffer pointersMatthijs Kooijman
Since the buffers aren't bigger than 64 bytes, these values can be smaller. This saves a few bytes of ram, but also saves around 50 bytes of program space, since the values can now be loaded using a single instruction. To prevent problems when people manually increase the buffer size, a compile-time check is added. Closes: #1078
2013-03-29Fix deprecated ISR names for ATmega8.Cristian Maglie
See #881
2013-03-29Removed deprecated interrupt handlersCristian Maglie
Fixes #831 #881 #955 #1123 #1140
2012-11-29Clarifying comment.David A. Mellis
2012-11-29Moving TXCO definition into HardwareSerial.cpp from HardwareSerial.h.David A. Mellis
Otherwise, you get an error when compiling for processors with no serial port because the header file is always compiled. See, for an example of the problem: https://github.com/damellis/attiny/issues/8
2012-08-30Changing setting of the UMSELn bits (for UART mode) and serial config values.David A. Mellis
Before, the UMSELn1 bit was being to set to 1, putting the UART into a reserved mode. Now, we only set the high (0x80) bit to 1 for the ATmega8, which is needed to access UCSRnC (whose i/o address is shared with UBRRH). Also, no longer bitwise-or the new config with the existing register value, because we're actually configuring all the settings in the register. (We're not using UCPOL, but it's supposed to be 0 in asynchronous mode.)
2012-08-30Merge pull request #109 from Alarus/masterDavid A. Mellis
Serial.begin() parameter to set data bits, parity, stop bits.
2012-08-28Serial.flush() waits for last character to be transmitted (michele.mazzucchi)David A. Mellis
http://code.google.com/p/arduino/issues/detail?id=871
2012-08-14Update hardware/arduino/cores/arduino/HardwareSerial.cppAlarus
New Serial.begin(baud, config);
2012-08-14Update hardware/arduino/cores/arduino/HardwareSerial.cppAlarus
New Serial.begin(baud, config);
2012-08-12Update hardware/arduino/cores/arduino/HardwareSerial.cppAlarus
Adding advanced begin (); with the ability to specify the length of bits, parity, stop bits.
2012-08-12Update hardware/arduino/cores/arduino/HardwareSerial.cppAlarus
Adding advanced begin (); with the ability to specify the length of bits, parity, stop bits.
2012-08-12Update hardware/arduino/cores/arduino/HardwareSerial.cppAlarus
Adding advanced begin (); with the ability to specify the length of bits, parity, stop bits.
2012-04-01added Boolean operators to HardwareSerial and CDC to test whether the port ↵Zach Eveland
is ready to send data. Mostly useful for Leonardo - simple way to test whether the port is actually opened by an application and ready to receive data. For Serial objects attached to real UARTs always returns true.
2012-02-03Making head and tail unsigned to avoid division in serial ISR.David A. Mellis
http://code.google.com/p/arduino/issues/detail?id=776
2011-10-10Fixing more warnings (Paul Stoffregen).David A. Mellis
2011-09-08Merge branch 'new-extension' of https://github.com/arduino/Arduino into ↵Zach Eveland
new-extension Conflicts: build/linux/dist/tools/avrdude.conf
2011-09-07Changing to a simpler mental model for serialEvent (Paul Stoffregen).David A. Mellis
http://code.google.com/p/arduino/issues/detail?id=626
2011-09-05changed baudrate for auto-reset-and-upload back to 1200 bps. specified ↵Zach Eveland
arduino protocol for Leonardo avrdude upload.
2011-09-05Merge branch 'new-extension' of https://github.com/arduino/Arduino into ↵Zach Eveland
new-extension Conflicts: build/macosx/dist/tools-universal.zip build/windows/avr_tools.zip hardware/arduino/cores/arduino/HardwareSerial.cpp
2011-08-31Moving serialEvent() calls from RX interrupts to main for() loop (after loop()).David A. Mellis
http://code.google.com/p/arduino/issues/detail?id=584
2011-08-30Merge branch 'mainline' into new-extensionZach Eveland
2011-08-26Moving write errors out of return value into separate API methods.David A. Mellis
write(), print(), println() now return size_t (and don't use negative values to signal errors). Print adds writeError() for checking for write errors, clearWriteError() to reset the flag to false, and a protected setWriteError() for signalling errors. http://code.google.com/p/arduino/issues/detail?id=598
2011-08-26Changing from long to ssize_t (int) for write(), print(), println() return.David A. Mellis
2011-08-23write(), print(), and println() now return number of bytes written.David A. Mellis
The type is long, and negative values indicate errors. Needs more testing. http://code.google.com/p/arduino/issues/detail?id=551
2011-08-18HW Serial on pins 0 and 1 works. Accessed by Serial1.* methodsZach Eveland
2011-08-11committed USB API, initial HardwareSerial-USBSerial integrationZach Eveland
2011-05-20Fixing 300 baud communication for serial.David A. Mellis
Because UBBR is only 12 bits, we were overflowing it at 300 baud because of the use of the U2X bit. Now we turn off U2X if it would yield a UBBR value that would overflow. Note that this breaks 300 baud communication with the computer on the Uno and Mega 2560 because the 8U2 USB-serial firmware has this same bug (and previously they cancelled each other out). Since, however, it seems more likely that people will need to use 300 baud to communicate with other (legacy) hardware than with the computer, I'm making this change. Issue for 8U2 firmware bug: http://code.google.com/p/arduino/issues/detail?id=542 http://code.google.com/p/arduino/issues/detail?id=522
2011-05-12Small optimization in HardwareSerial.David A. Mellis
begin(long) -> begin(unsigned long) Conflicts: hardware/arduino/cores/arduino/HardwareSerial.h
2011-05-07Adding serialEvent(), serialEvent1(), etc.David A. Mellis
Called from within the serial receive interrupt. These are implemented as an empty weak function in the core that be overridden by the user's sketch. http://code.google.com/p/arduino/issues/detail?id=263
2011-05-07Refactoring the UART0 / USART0 receive interrupt handler.David A. Mellis
2011-05-07Changing Serial.flush() to write outgoing data, not drop incoming data.David A. Mellis
This brings it in line with most other uses of flush(), both in and out of Arduino. http://code.google.com/p/arduino/issues/detail?id=497
2011-03-06Flushing outgoing and incoming data in Serial.end().David A. Mellis
That is, waiting for outgoing data to transmit and dropping any received data.
2011-03-06Fixing race condition in Serial write (Brian Cook).David A. Mellis
2011-03-05Implemented serial transmit buffering.David A. Mellis
Now Serial.write() places characters in the transmit buffer, and the data register empty interrupt reads and transmit them. Based loosely on the implementation here: ftp://wookey.org.uk/arduino. http://code.google.com/p/arduino/issues/detail?id=262
2011-03-01Moving wiring.h contents into Arduino.h.David A. Mellis
2010-11-11Cast to encourage optimization of Serial ring buffer index calculations.David A. Mellis
http://code.google.com/p/arduino/issues/detail?id=391
2010-11-11Changing baud rate calculation to always use double speed mode except for ↵David A. Mellis
57600 baud at 16 MHz. http://code.google.com/p/arduino/issues/detail?id=394
2010-10-17Making HardwareSerial tests register-based, not CPU-based.David A. Mellis
Mark Sproul's patches, via Christian Maglie. http://code.google.com/p/arduino/issues/detail?id=315
2010-09-081280 -> 1280/2560.David A. Mellis
2010-08-02changing available() to return an int (because the Ethernet Client class or ↵David A. Mellis
another stream might need more than 255 bytes).
2010-07-04Adding a peek() function to Stream and HardwareSerial (Serial).David A. Mellis
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