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VS8053b Datasheet

FUNCTIONAL DESCRIPTION

9.6.5

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 (Ogg Vorbis) can also indicate the absolute play position, see the

positionMsec

extra parameter in section 10.10.

9.6.6

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 digital power consumption when idle, you can write a low samplerate to SCI_AUDATA.

Note: Ogg Vorbis decoding overrides AUDATA change. If you want to ﬁne-tune samplerate in

streaming applications with Ogg Vorbis, use SCI_CLOCKF to control the playback rate instead

of AUDATA.

9.6.7

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.

Version: 1.31, 2017-11-17

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