Conversion word 0
Conversion word 1
Conversion word 2
Conversion word 62
Conversion word 63
0xFF3E00FC
0xFF3E01F8
0xFF3E0008
0xFF3E0004
0xFF3E0000
ADC1
0xFF3A00FC
0xFF3A01F8
0xFF3A0008
0xFF3A0004
0xFF3A0000
ADC2
Basic Operation
857
SPNU563A – March 2018
Copyright © 2018, Texas Instruments Incorporated
Analog To Digital Converter (ADC) Module
22.2.1.9.2 Reading Conversion Results Directly from the Conversion Results’ Memory
The conversion result memory is part of the device’s memory map. The base address for the ADC1 result
memory is FF3E 0000h and for the ADC2 result memory is FF3A 0000h.
Figure 22-6. ADC Memory Mapping
The application can identify the address ranges for each of the three memory regions for the three
conversion groups after performing the segmentation as described in
. It is up to the
application to read the desired results from the three conversion groups. The formats of the conversion
results when reading from RAM directly are shown in
and
Figure 22-7. Format of Conversion Result Directly Read from ADC RAM, 12-bit ADC
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
ADC RAM
address
Reserved
channel id [4]
channel id [3–0]
12-bit conversion result
Figure 22-8. Format of Conversion Result Directly Read from ADC RAM, 10-bit ADC
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
ADC RAM
address
Reserved
Rsvd
channel id [4–0]
10-bit conversion result
Note that there is no EMPTY field to protect the application from reading data that has been previously
read.
Each group does have a separate register which holds the address in the group’s result memory where
the ADC will write the next conversion result. These are the ADEVRAMWRADDR, ADG1RAMWRADDR,
and ADG2RAMWRADDR registers. The application can use this information to calculate how many valid
conversion results are available to be read.
Benefit of reading conversion results directly from ADC RAM:
The application does not have to read out conversion results sequentially as in the case of reading from a
FIFO. As a result, the application can selectively read the conversion results for any particular input
channel of interest without having to read other channels’ conversion results.