Datasheet

VS1053b Datasheet
10 OPERATION
10.12 SDI Tests
There are several test modes in VS1053b, which allow the user to perform memory tests, SCI
bus tests, and several different sine wave tests.
All tests, except for the New Sine and Sweep Tests, are started in a similar way: do a hardware
reset to VS1053b, then set register SM_MODE bit SM_TESTS, and then send a test command
sequence 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.
10.12.1 Old 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:
n bits
Name Bits Description
F
s
Idx 7:5 Samplerate index
S 4:0 Sine skip speed
F
s
Idx F
s
F
s
Idx F
s
0 44100 Hz 4 24000 Hz
1 48000 Hz 5 16000 Hz
2 32000 Hz 6 11025 Hz
3 22050 Hz 7 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 compo-
nents, F
s
Idx = 0b011 = 3 and thus F
s
= 22050Hz. S = 0b11110 = 30, and thus the final sine
frequency F = 22050Hz ×
30
128
≈ 5168Hz.
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: 1.22, 2014-12-19 66