mc9s12xs128 Freescale Semiconductor, Inc, mc9s12xs128 Datasheet - Page 277

• Manufacturer Part Number: mc9s12xs128
• Description: Hcs12 Microcontrollers 16-bit Automotive Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

10.3.2.2
Writes to this register will abort current conversion sequence.
Read: Anytime
Write: Anytime
Freescale Semiconductor
ETRIGCH[3:0]
Module Base + 0x0001
ETRIGSEL
SRES[1:0]
SMP_DIS
Reset
Field
6–5
3–0
W
7
4
R
ETRIGSEL
ATD Control Register 1 (ATDCTL1)
0
7
External Trigger Source Select — This bit selects the external trigger source to be either one of the AD
channels or one of the ETRIG3-0 inputs. See device specification for availability and connectivity of ETRIG3-
0 inputs. If a particular ETRIG3-0 input option is not available, writing a 1 to ETRISEL only sets the bit but has
not effect, this means that one of the AD channels (selected by ETRIGCH3-0) is configured as the source for
external trigger. The coding is summarized in
A/D Resolution Select — These bits select the resolution of A/D conversion results. See
coding.
Discharge Before Sampling Bit
0 No discharge before sampling.
1 The internal sample capacitor is discharged before sampling the channel. This adds 2 ATD clock cycles to
External Trigger Channel Select — These bits select one of the AD channels or one of the ETRIG3-0 inputs
as source for the external trigger. The coding is summarized in
1
the sampling time. This can help to detect an open circuit instead of measuring the previous sampled
channel.
If only AN0 should be converted use MULT=0.
SRES1
0
6
SRES1
Figure 10-4. ATD Control Register 1 (ATDCTL1)
0
0
1
1
Table 10-3. ATDCTL1 Field Descriptions
S12XS Family Reference Manual, Rev. 1.10
SRES0
Table 10-4. A/D Resolution Coding
1
5
SRES0
0
1
0
1
SMP_DIS
0
4
Table
Description
10-5.
ETRIGCH3
A/D Resolution
10-bit data
12-bit data
Reserved
1
8-bit data
3
Table
Analog-to-Digital Converter (ADC12B16CV1)
ETRIGCH2
10-5.
1
2
ETRIGCH1
1
1
Table 10-4
ETRIGCH0
for
1
0
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