DS80CH11 Datasheet, PDF (47/88 Pages) Dallas Semiconductor – System Energy Manager

DS80CH11
A/D CONVERSION TIMES (µS)
PRESCALE
SETTING
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
0.640
MHz
100.00
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
4.000
MHz
16.00
32.00
48.00
64.00
80.00
96.00
–
–
–
–
–
–
–
–
–
–
8.000
MHz
–
16.00
24.00
32.00
40.00
48.00
56.00
64.00
72.00
80.00
88.00
96.00
–
–
–
–
12.000
MHz
–
–
16.00
21.33
26.67
32.00
37.33
42.67
48.00
53.33
58.67
64.00
69.33
74.67
80.00
85.33
16.000
MHz
–
–
–
16.00
20.00
24.00
28.00
32.00
36.00
40.00
44.00
48.00
52.00
56.00
60.00
64.00
20.000
MHz
–
–
–
–
16.00
19.20
22.40
25.60
28.80
32.00
35.20
38.40
41.60
44.80
48.00
51.20
25.000
MHz
–
–
–
–
–
–
17.92
20.48
23.04
25.60
28.16
30.72
33.28
35.84
38.40
40.96
NOTES:
1. Conversion times given in microseconds (µs)
2. ( – ) = not a usable setting
7.6 WINDOW COMPARATOR
The window comparator allows software to identify a
range of potential digital A/D results that are considered
interesting. The window comparator will monitor each
conversion result against user programmed selections.
Results that meet the criteria will cause the comparator
to set the WCM flag. By setting the WCQ bit, the end of
conversion interrupt source is qualified so that only
results which fall within the programmed range cause
the interrupt. This feature allows software to ignore
uninteresting results without actually reading the con-
verter result.
User software can select two 8–bit comparator values.
These values will be compared against the most signifi-
cant 8–bits of each A/D result, designated as ADR9–2.
The user also can identify whether the target result is
inside of the range bounded by the upper and lower limit
or outside through programming of the WCIO bit. In
practice, this allows the comparator to look for A/D
results that are above a number, below a number, inside
of a range, or outside of a range. The state of the WCM
flag can be expressed by the following Boolean equa-
tion:
WCM = WCIO ⊕ (WINHI < ADR9–2) ⊕ (WINLO <
ADR9–2)
Figure 7–3 illustrates the ranges that can be examined
using the window comparator.
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