Datasheet

VS1053b Datasheet
10 OPERATION
10.12.2 New Sine and Sweep Tests
A more frequency-accurate sine test can be started and controlled from SCI. SCI_AICTRL0 and
SCI_AICTRL1 set the sine frequencies for left and right channel, respectively. These registers,
volume (SCI_VOL), and samplerate (SCI_AUDATA) can be set before or during the test. Write
0x4020 to SCI_AIADDR to start the test.
SCI_AICTRLn can be calculated from the desired frequency and DAC samplerate by:
SCI_AICTRLn = F
sin
× 65536/F
s
The maximum value for SCI_AICTRLn is 0x8000U. For the best S/N ratio for the generated
sine, three LSb’s of the SCI_AICTRLn should be zero. The resulting frequencies F
sin
can be
calculated from the DAC samplerate F
s
and SCI_AICTRL0 / SCI_AICTRL1 using the following
equation.
F
sin
= SCI_AICTRLn × F
s
/65536
Sine sweep test can be started by writing 0x4022 to SCI_AIADDR.
Both these tests use the normal audio path, thus also SCI_BASS, differential output mode, and
EarSpeaker settings have an effect.
10.12.3 Pin Test
Pin test is activated with the 8-byte sequence 0x50 0xED 0x6E 0x54 0 0 0 0. This test is meant
for chip production testing only.
10.12.4 SCI Test
Sci test is initialized with the 8-byte sequence 0x53 0x70 0xEE n 0 0 0 0, where n is the
register number to test. The content of the given register is read and copied to SCI_HDAT0. If
the register to be tested is HDAT0, the result is copied to SCI_HDAT1.
Example: if n is 0, contents of SCI register 0 (SCI_MODE) is copied to SCI_HDAT0.
Version: 1.22, 2014-12-19 67