Many register and bit references in this document are written in general form. A lower case ā€œnā€ replaces the Timer/Counter number, in this case 0. However, when using the register or bit defines in a program, the precise form must be used i.e. TCNT0 for accessing Timer/Counter0 counter value and so on.

The definitions in the table below are also used extensively throughout this datasheet.

Table 1. Definitions
BOTTOM The counter reaches the BOTTOM when it becomes 0x00
MAX The counter reaches its MAXimum when it becomes 0xFF (decimal 255)