VS1053B Datasheet, PDF (43/79 Pages) List of Unclassifed Manufacturers – Ogg Vorbis/MP3/AAC/WMA/MIDI AUDIO CODEC

VLSI
Solution ^y
VS1053b preliminary
VS1053B
8. FUNCTIONAL DESCRIPTION
8.7.5 SCI DECODE TIME (RW)
When decoding correct data, current decoded time is shown in this register in full seconds.
The user may change the value of this register. In that case the new value should be written twice to
make absolutely certain that the change is not overwritten by the firmware.
A write to SCI DECODE TIME also resets the byteRate calculation.
SCI DECODE TIME is reset at every hardware and software reset. It is no longer cleared when decoding
of a file ends to allow the decode time to proceed automatically with looped files and with seamless
playback of multiple files.
With fast playback (see the playSpeed extra parameter) the decode time also counts faster.
Some codecs (WMA and Ogg Vorbis) can also indicate the absolute play position, see the positionMsec
extra parameter in section 9.11.
8.7.6 SCI AUDATA (RW)
When decoding correct data, the current samplerate and number of channels can be found in bits 15:1
and 0 of SCI AUDATA, respectively. Bits 15:1 contain the samplerate divided by two, and bit 0 is 0 for
mono data and 1 for stereo. Writing to SCI AUDATA will change the samplerate directly.
Example: 44100 Hz stereo data reads as 0xAC45 (44101).
Example: 11025 Hz mono data reads as 0x2B10 (11024).
Example: Writing 0xAC80 sets samplerate to 44160 Hz, stereo mode does not change.
To reduce the digital power consumption when in idle, you can write a low samplerate to SCI AUDATA.
8.7.7 SCI WRAM (RW)
SCI WRAM is used to upload application programs and data to instruction and data RAMs. The start
address must be initialized by writing to SCI WRAMADDR prior to the first write/read of SCI WRAM.
As 16 bits of data can be transferred with one SCI WRAM write/read, and the instruction word is 32 bits
long, two consecutive writes/reads are needed for each instruction word. The byte order is big-endian (i.e.
most significant words first). After each full-word write/read, the internal pointer is autoincremented.
8.7.8 SCI WRAMADDR (W)
SCI WRAMADDR is used to set the program address for following SCI WRAM writes/reads. Address
offset of 0 is used for X, 0x4000 for Y, and 0x8000 for instruction memory. Peripheral registers can also
be accessed.
Version 0.5, 2007-12-03
43