I have been trying to grasp a better understand of registers and port manipulation. I have been looking through the ATmega 328P datasheet to look at the different registers.
For some of the registers, I see that there are two addresses listed. For example, for PORTB is listed at 0x05 (0x25). Similarly, for its DDRB and PINB, they are listed at 0x04 (0x24), and 0x03 (0x23), respectively. What does this mean for the register? Thank you.