VS1002D Datasheet, PDF (21/54 Pages) List of Unclassifed Manufacturers – MP3 AUDIO CODEC

VLSI
Solution ^y
VS1002d
VS1002D
7. SPI BUSES
7.7 SPI Examples with SM SDINEW and SM SDISHARED set
7.7.1 Two SCI Writes
SCI Write 1
SCI Write 2
XCS
0
1
2
3
SCK
SI
0
0
0
0
30 31
10
X
32 33
0
0
61 62 63
2
1
0
X
Figure 9: Two SCI Operations.
Figure 9 shows two consecutive SCI operations. Note that xCS must be raised to inactive state between
the writes.
7.7.2 Two SDI Bytes
SDI Byte 1
XCS
0
1
2
3
SCK
7
6
5
4
3
SI
67
10
SDI Byte 2
8
9
13 14 15
7
6
5
2
1
0
X
Figure 10: Two SDI Bytes.
SDI data is synchronized with a raising edge of xCS as shown in Figure 10. However, every byte doesn’t
need separate synchronization.
7.7.3 SCI Operation in Middle of Two SDI Bytes
SDI Byte
SCI Operation
XCS
SCK
0
1
6
7
89
38 39
7
6
51
0
SI
00
1
0
SDI Byte
40 41
46 47
7
6
5
1
0
X
Figure 11: Two SDI Bytes Separated By an SCI Operation.
Figure 11 shows how an SCI operation is embedded in between SDI operations. The changes in xCS are
used to synchronize both SDI and SCI.
Version 1.0, 2005-04-27
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