STA013 datasheet(9/38 Pages) STMICROELECTRONICS

9 / 38 page

2.5 - STA013 Operation Mode

The STA013 can work in two different modes,

called Multimedia Mode and Broadcast Mode.

In Multimedia Mode, STA013 decodes the in-

coming bitstream, acting as a master of the data

communication from the source to itself.

This control is done by a specific buffer manage-

ment, controlled by STA013 embedded software.

The data source, by monitoring the DATA_REQ

line, send to STA013 the input data, when the

signal is high (default configuration).

The

communication

stopped

when

the

DATA_REQ line is low.

In this mode the fractional part of the PLL is dis-

abled and the audio clocks are generated at

nominal rates. Fig. 9 describes the default

DATA_REQ signal behaviour.

Programming STA013 it is possible to invert the

polarity

the

DATA_REQ

line

(register

REQ_POL).

In Broadcast Mode, STA013 works receiving a

bitstream with the input speed regulated by the

source. In this configuration the source has to

guarantee that the bitrate is equivalent to the

nominal bitrate of the decoded stream.

To compensate the difference between the nomi-

nal and the real sampling rates, the STA013 em-

bedded software controls the fractional PLL op-

eration. Portable or Mobile applications need

normally to operate in Broadcast Mode. In both

modes the MPEG Synchronisation is automatic

and transparent to the user. To operate in Multi-

media mode, the STA013, pin nr. 8, SCR-INT

must be connected to VDD on the application

board.

2.6 - STA013 Decoding States

There are three different decoder states: Idle,

Init, and Decode. Commands to change the de-

coding states are described in the STA013 I

registers description.

Idle Mode

In this mode the decoder is waiting for the RUN

command. This mode should be used to initialise

the configuration register of the device. The DAC

connected to STA013 can be initialised during

this mode (set MUTE to 1).

PLAY

MUTE

Clock State

PCM Output

Not Running

Running

Init Mode

"PLAY" and "MUTE" changes are ignored in this

mode. The internal state of the decoder will be

updated only when the decoder changes from the

state "init" to the state "decode". The "init" phase

ends when the first decoded samples are at the

output stage of the device.

Decode Mode

This mode is completely described by the follow-

ing table:

PLAY

MUTE

Clock State

PCM

Output

Decoding

Not Running

Running

Decoded

Samples

Yes

Running

Yes

3 - I

2C BUS SPECIFICATION

The STA013 supports the I

2C protocol. This pro-

tocol defines any device that sends data on to the

bus as a transmitter and any device that reads

the data as a receiver. The device that controls

the data transfer is known as the master and the

others as the slave. The master always starts the

transfer and provides the serial clock for synchro-

nisation. The STA013 is always a slave device in

all its communications.

3. 1 - COMMUNICATION PROTOCOL

3.1.0 - Data transition or change

Data changes on the SDA line must only occur

when the SCL clock is low. SDA transition while

the clock is high are used to identify START or

STOP condition.

3.1.1 - Start condition

START is identified by a high to low transition of

the data bus SDA signal while the clock signal

SCL is stable in the high state.

A START condition must precede any command

for data transfer.

SOURCE SEND DATA TO STA013

DATA_REQ

SOURCE STOPS TRANSMITTING DATA

D98AU913

Figure 9.

STA013 - STA013B - STA013T

9/38

STA013 数据表(PDF) 9 Page - STMicroelectronics

STA013 数据表(HTML) 9 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38

数据表下载

链接网址

STA013 数据表(PDF) 9 Page - STMicroelectronics

STA013 数据表(HTML) 9 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38

数据表 下载

链接网址

数据表下载