These chips were previously supported, but since parity error checking
was added, this support has broken. Most chips define UPE0 (etc.) for
the parity error bit. Some chips don't have numbered UARTS so only
define UPE and even fewer define PE instead of UPE. This adds support
for those chips again.
Closes: #2137
This was already fixed for HardwareSerial.cpp in #1863, but there was
one more case hidden in HardwareSerial_private.h.
The index attributes have been uint8_t for a while, so there is no point
in using int for local variables. This should allow the compiler to
generate slightly more efficient code, but (at least on gcc 4.8.2) it
also confuses the register allocator, causing this change to increase
code size by 2 bytes instead due to extra push/pop instructions (but
this will probably change in the future if the compiler improves).
Switch the tx and rx buffer head/tail entries in the HardwareSerial
initialisation list so that they match the order the fields are defined
in. This fixes a compiler warning (repeated for each of the
HardwareSerial source files the header is used in).
Moreover, declaring pointers-to-registers as const and using initializer
list in class constructor allows the compiler to further improve inlining
performance.
This change recovers about 50 bytes of program space on single-UART devices.
See #1711
Matthijs Kooijman
Cristian Maglie
jantje
Matt Robinson