SAM4L Datasheet, PDF (997/1185 Pages) ATMEL Corporation – ATSAM ARM-based Flash MCU

ATSAM4L4/L2
Figure 38-3. Two DMA Tx transfers: With Window Mode Configuration
DMA Tx Ready
Start Of Conversion
APB Data Bus
MSB : 1
1st DMA Word Data
MSB : 0
2nd DMA Word Data
CDMA Register
31
30
29
28
1
ZOOMRANGE
23
22
21
20
MUXNEG
15
14
INTERNAL
13
12
TSS RES
7
6
5
4
GCOMP
GAIN
27
19
11
3
STRIG
26
25
18
17
MUXPOS
10
9
2
1
BIPOLAR
24
16
8
ENSTUP
0
HWLA
First DMA Word Data with MSB to "1"
CDMA Register
31
30
29
28
27
26
25
24
0
HT[11:8]
23
22
21
20
19
18
17
16
HT[7:0]
15
14
13
12
11
10
9
8
WM
LT[11:8]
7
6
5
4
3
2
1
0
LT[7:0]
Second DMA Word Data with MSB to "0"
38.6.16
Zoom Mode
The Zoom mode allows to choose a part of a range of the reference voltage
(SEQCFG.ZOOMRANGE) and spread it from 0 to 4095 decimal. This particular mode of the
ADC uses GAIN in which the input range is shifted with a programmable voltage.
The input voltage range is acording to a programmable voltage of Vdd and a range around this
voltage (SEQCFG.GAIN).
38.6.17
Window Monitor
The window monitor monitors ADC results and make the ADCIFE behave as an analog compar-
ator. Configuration is done by writing appropriately the Window Configuration Register (WCFG)
and the Window Thresholds Register (WTH). When writing a one in the Monitor Filter Mode bit in
the WCFG register (WCFG.MFM) , conversions are filtered using its index in the sequence. Oth-
erwise, no filtering is applied, monitoring is performed on every conversion. Index is given by
writing the field Source in the WCFG register (WCFG.SRC). Supported modes are selected by
writing the Window Mode field in the WCFG register, refer to the Table 38-3 below.
Thresholds are given by writing the Low Threshold (LT) and High Threshold (HT) in WTH. Note
that the significant WTH.LT and WT.HT bits are given by the precision selected in the
SEQCFG.RES field. That means that if you are in 8-bit mode, only the 8 lower bits will be
considered.
42023C–SAM–02/2013
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