Atmel SAM4L Xplained Pro Evaluation Kit Atmel ATSAM4L-XPRO ATSAM4L-XPRO Data Sheet

42023E–SAM–07/2013

• On toggle of the window compare output (ACWOUT).

• When the comparison in both ACs in the window mode is ready.

• When the common input voltage enters the window (i.e., rising-edge of ACWOUT).

• When the common input voltage leaves the window (i.e., falling-edge of ACWOUT).

When operating in window mode, each AC can generate the same peripheral events as in nor-
mal mode, see 

Additionally, user enables generation of window peripheral events by writing a one to the Win-
dow Peripheral Event Enable bit (CONFWx.WFEN).

Writing to Window Mode Peripheral Event Selection Source (CONFWx.WEVSRC) selects the
peripheral events source:

• As soon as the common input voltage is inside the window.

• As soon as the common input voltage is outside the window.

• On toggle of the window compare output (ACWOUT) 

• Whenever a comparison is ready and the common input voltage is inside the window.

• Whenever a comparison is ready and the common input voltage is outside the window.

• When the comparison of both ACs in the window mode is ready.

The user can select the hysteresis voltage used by each AC to reduce noise in its output. As
shown in 

, the output of the AC switches from zero to one when the differential volt-

age V

D

 (= V

INP 

- V

INN

) is greater than (hysteresis voltage / 2) and switches from one to zero when

V

D

 is less than (hysteresis voltage / 2). The hysteresis voltage for each AC is selected by writing

to the Hysteresis Voltage field in the CONFx register (CONFx.HYS), as shown in 

Figure 37-3. Hysteresis Voltage

ACOUT

V

D

 = V

INP

 – V

INN

VDD

Hysteresis Voltage

Hysteresis Voltage Selection

0

0

1

25

2

50

3

75