Datasheet

136

ATmega169A/PA/329A/PA/649A/P/3290A/PA/6490A/P [DATASHEET]

8284E–AVR–02/2013

clock frequency and duty cycle caused by Oscillator source (XTAL, resonator, and capacitors) tolerances, it is rec-

ommended that maximum frequency of an external clock source is less than f

clk_I/O

/2.5.

An external clock source can not be prescaled.

Figure 17-2. Prescaler for Timer/Counter0 and Timer/Counter1

(1)

Note: 1. The synchronization logic on the input pins (T1/T0) is shown in Figure 17-1 on page 135.

PSR10

Clear

clk

I/O

Synchronization