Data Sheet

PRELIMINARY
VS1063a Datasheet
10 OPERATION
Notice that reading two-word variables through the SCI_WRAMADDR and SCI_WRAM inter-
face is only partly atomic. In VS1063 a write to SCI_WRAMADDR reads ahead two words that
it provides to SCI_WRAM, so the two halfs of a long variable are sampled together. But as the
write to the variable may not be protected from interrupts, the SCI interrupt may occur between
the update of the low and high parts of the variable.
It is quite improbable though. If you want to make certain the value is correct, read it twice and
compare the results.
10.11.3 VU Meter
Parameter Address Usage
playMode 0x1e09 bit 2: VU meter enable
vuMeter 0x1e0c VU meter result (if VU meter enabled)
VU Meter takes the absolute maximum of the output samples and reports it in 3dB steps from
0 to 32, separately for left and right channel. Bits 15. . . 8 of contain the
left channel result, bits 7. . . 0 contain the right channel result.
VU Meter uses about 0.2MHz of processing power at 48 kHz samplerate.
Version: 0.42, 2011-11-24 68