4-38
AT90S8414
Preliminary
Timer/Counter1 can also be used as a 10 bit Pulse With Modulator. In this mode the counter and the OCR1A/OCR1B
registers serve as a dual glitch-free stand-alone PWM with centered pulses. Refer to Page 4-42 for a detailed description
on this function.
The Input Capture function of Timer/Counter1 provides a capture of the Timer/Counter1 contents to the Input Capture
Register - ICR1, triggered by an external event on the Input Capture Pin - ICP. The actual capture event settings are
defined by the Timer/Counter1 Control Register - TCCR1B. In addition, the Analog Comparator can be set to trigger the
Input Capture. Refer to the paragraph, “The Analog Comparator”, for details on this. The ICP pin logic is shown in
Figure 34.
Figure 34: ICP Pin Schematic Diagram
The Timer/Counter1 input capture noise canceler block diagram is shown in Figure 35.
Figure 35: The Input Capture Noise Canceler
If the noise canceler function is enabled, the actual trigger condition for the capture event is monitored over 4 samples
before the capture is activated. The sampling clock is the same clock as the clock source selected for the Timer/Counter1.
