noob need help with language question

Projects Programming
1

I'm new to Arduino and have an UNO. I'm working on a motor control project using PWM. I'm new to Arduino but have been a programmer of microcontrollers for many years both in assembly and C. My question comes from an article I found called the SecretsPfArduinoPWM where the line

TCCR2A = _BV(COM2A1) | etc.

I understand that this is setting the register TCCR2A with a value. I am unfamiliar with the _BV. Is this to set a bit value? Is it a define or a macro defines somewhere? I've tried searching the Arduino reference but can't find _BV().
thanks.

2

Yes, bit value. Equivalent to:

TCCR2A = (1<<COM2A1);
3

Thanks. Is this documented somewhere in the reference?

4

https://www.microchip.com/webdoc/AVRLibcReferenceManual/group__avr__sfr_1ga11643f271076024c395a93800b3d9546.html

5

thanks very much. I had been reading the ATmega328P data sheet so I've got a better idea of what's happening. The link you sent me for microchip reference will be very helpful.

By the way, on the paper https://www.arduino.cc/en/Tutorial/SecretsOfArduinoPWM there is a link that suggests I can get the code for the fragment talking about fast PWM, but the link appears broken.