mc9s12vr48 Freescale Semiconductor, Inc, mc9s12vr48 Datasheet - Page 271

• Manufacturer Part Number: mc9s12vr48
• Description: S12 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

8.3.2.12
The A/D conversion results are stored in 6 result registers. Results are always in unsigned data
representation. Left and right justification is selected using the DJM control bit in ATDCTL3.
If automatic compare of conversions results is enabled (CMPE[n]=1 in ATDCMPE), these registers must
be written with the compare values in left or right justified format depending on the actual value of the
DJM bit. In this case, as the ATDDRn register is used to hold the compare value, the result will not be
stored there at the end of the conversion but is lost.
Attention, n is the conversion number, NOT the channel number!
Read: Anytime
Write: Anytime
8.3.2.12.1
Table 8-21
result registers for left justified data. Compare is always done using all 12 bits of both the conversion result
and the compare value in ATDDRn.
Freescale Semiconductor
Module Base +
0x0010 = ATDDR0, 0x0012 = ATDDR1, 0x0014 = ATDDR2, 0x0016 = ATDDR3
0x0018 = ATDDR4, 0x001A = ATDDR5
Reset
W
R
15
0
shows how depending on the A/D resolution the conversion result is transferred to the ATD
ATD Conversion Result Registers (ATDDRn)
= Unimplemented or Reserved
For conversions not using automatic compare, results are stored in the result
registers after each conversion. In this case avoid writing to ATDDRn except
for initial values, because an A/D result might be overwritten.
Left Justified Result Data (DJM=0)
14
0
Figure 8-14. Left justified ATD conversion result register (ATDDRn)
13
0
resolution
10-bit data
12-bit data
8-bit data
Table 8-21. Conversion result mapping to ATDDRn
A/D
12
0
MC9S12VR Family Reference Manual, Rev. 2.2
Preliminary - Subject to Change Without Notice
11
0
0
0
0
DJM
Result-Bit[11:0]
10
0
Result-Bit[11:4] = conversion result,
Result-Bit[3:0]=0000
Result-Bit[11:2] = conversion result,
Result-Bit[1:0]=00
Result-Bit[11:0] = result
conversion result mapping to
9
0
NOTE
0
8
0
7
0
6
Analog-to-Digital Converter (ADC12B6CV2)
ATDDRn
5
0
0
4
0
0
3
0
0
2
0
0
1
0
0
0
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