VS1011 Datasheet, PDF (33/43 Pages) List of Unclassifed Manufacturers – MP3 AUDIO CODEC

VLSI
Solution ^y
VS1011 PRELIMINARY
VS1011
9. OPERATION
9.5 Feeding PCM data
VS1011 can be used as a PCM decoder by sending to it a WAV file header. If the length sent in the WAV
file is 0 or 0xFFFFFFF, VS1011 will stay in PCM mode indefinitely. 8-bit linear and 16-bit linear audio
is supported in mono or stereo.
9.6 SDI Tests
There are several test modes in VS1011, which allow the user to perform memory tests, SCI bus tests,
and several different sine wave tests.
All tests are started in a similar way: VS1011 is hardware reset, SM TESTS is set, and then a test
command is sent to the SDI bus. Each test is started by sending a 4-byte special command sequence,
followed by 4 zeros. The sequences are described below.
9.6.1 Sine Test
Sine test is initialized with the 8-byte sequence 0x53 0xEF 0x6E n 0 0 0 0, where n defines the sine test
to use. n is defined as follows:
Name
F _sIdx
S
n bits
Bits Description
7:5 Sample rate index
4:0 Sine skip speed
F _sIdx
0
1
2
3
4
5
6
7
F_s
44100 Hz
48000 Hz
32000 Hz
22050 Hz
24000 Hz
16000 Hz
11025 Hz
12000 Hz
The
frequency
of the
sine
to
be output
can
now be
calculated
from
F
=
F_s
×
S
128
.
Example: Sine test is activated with value 126, which is 0b01111110. Breaking n to its components,
F _sIdx = 0b011 = 1 and thus F _s = 22050Hz. S = 0b11110 = 30, and thus the final sine frequency
F
=
22050H z
×
30
128
≈
5168H z .
To exit the sine test, send the sequence 0x45 0x78 0x69 0x74 0 0 0 0.
Note: Sine test signals go through the digital volume control, so it is possible to test channels separately.
Version 0.71, 2004-07-20
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