SD16_A Operation
28-10
SD16_A
Digital Filter Output
The number of bits output by the digital filter is dependent on the oversampling
ratio and ranges from 15 to 30 bits. Figure 28−6 shows the digital filter output
and their relation to SD16MEMx for each OSR, LSBACC, and SD16UNI
setting. For example, for OSR = 1024, LSBACC = 0, and SD16UNI = 1, the
SD16MEMx register contains bits 28 − 13 of the digital filter output. When
OSR = 32, the one (SD16UNI = 0) or two (SD16UNI = 1) LSBs are always
zero.
The SD16LSBACC and SD16LSBTOG bits give access to the least significant
bits of the digital filter output. When SD16LSBACC = 1 the 16 least significant
bits of the digital filter’s output are read from SD16MEMx using word
instructions. The SD16MEMx register can also be accessed with byte
instructions returning only the 8 least significant bits of the digital filter output.
When SD16LSBTOG = 1 the SD16LSBACC bit is automatically toggled each
time SD16MEMx is read. This allows the complete digital filter output result to
be read with two reads of SD16MEMx. Setting or clearing SD16LSBTOG does
not change SD16LSBACC until the next SD16MEMx access.
Figure 28−6. Used Bits of Digital Filter Output
0
4
8
12
16
20
24
1
5
3
2
6
9
7
23 22 21
19 18 17
15 14 13
11 10
28 27 26 25
29
OSR=512, LSBACC=0, SD16UNI=0
0
4
8
12
16
20
24
1
5
3
2
6
9
7
23 22 21
19 18 17
15 14 13
11 10
28 27 26 25
29
OSR=512, LSBACC=1, SD16UNI=0
0
4
8
12
16
20
24
1
5
3
2
6
9
7
23 22 21
19 18 17
15 14 13
11 10
28 27 26 25
29
OSR=512, LSBACC=0, SD16UNI=1
0
4
8
12
16
20
24
1
5
3
2
6
9
7
23 22 21
19 18 17
15 14 13
11 10
28 27 26 25
29
OSR=512, LSBACC=1, SD16UNI=1
0
4
8
12
16
20
24
1
5
3
2
6
9
7
23 22 21
19 18 17
15 14 13
11 10
28 27 26 25
29
OSR=1024, LSBACC=0, SD16UNI=0
0
4
8
12
16
20
24
1
5
3
2
6
9
7
23 22 21
19 18 17
15 14 13
11 10
28 27 26 25
29
OSR=1024, LSBACC=1, SD16UNI=0
0
4
8
12
16
20
24
1
5
3
2
6
9
7
23 22 21
19 18 17
15 14 13
11 10
28 27 26 25
29
OSR=1024, LSBACC=0, SD16UNI=1
0
4
8
12
16
20
24
1
5
3
2
6
9
7
23 22 21
19 18 17
15 14 13
11 10
28 27 26 25
29
OSR=1024, LSBACC=1, SD16UNI=1
Summary of Contents for MSP430x4xx Family
Page 1: ...MSP430x4xx Family 2007 Mixed Signal Products User s Guide SLAU056G ...
Page 2: ......
Page 6: ...vi ...
Page 114: ...3 76 RISC 16 Bit CPU ...
Page 304: ...5 20 FLL Clock Module ...
Page 340: ...7 8 Supply Voltage Supervisor ...
Page 348: ...8 8 16 Bit Hardware Multiplier ...
Page 372: ...9 24 32 Bit Hardware Multiplier ...
Page 400: ...10 28 DMA Controller ...
Page 428: ...13 10 Basic Timer1 ...
Page 466: ...15 24 Timer_A ...
Page 522: ...17 30 USART Peripheral Interface UART Mode ...
Page 544: ...18 22 USART Peripheral Interface SPI Mode ...
Page 672: ...23 12 Comparator_A ...
Page 692: ...24 20 LCD Controller ...
Page 746: ...26 28 ADC12 ...