
90
2513L–AVR–03/2013
ATmega162/V
The double buffered Output Compare Register (OCR0) is compared with the Timer/Counter
value at all times. The result of the compare can be used by the Waveform Generator to gener-
ate a PWM or variable frequency output on the Output Compare pin (OC0).
See “Output(OCF0) which can be used to generate an output compare interrupt request.
Definitions
Many register and bit references in this section are written in general form. A lower case “n”
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
Table 46 are also used extensively throughout the document.
Timer/Counter
Clock Sources
The Timer/Counter can be clocked by an internal or an external clock source. The clock source
is selected by the Clock Select logic which is controlled by the Clock Select (CS02:0) bits
located in the Timer/Counter Control Register (TCCR0). For details on clock sources and pres-
Table 46. Definitions
BOTTOM
The counter reaches the BOTTOM when it becomes 0x00.
MAX
The counter reaches its MAXimum when it becomes 0xFF (decimal 255).
TOP
The counter reaches the TOP when it becomes equal to the highest
value in the count sequence. The TOP value can be assigned to be the
fixed value 0xFF (MAX) or the value stored in the OCR0 Register. The
assignment is dependent on the mode of operation.