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TDA7522

Figure 3. ST7 Interface Overview

ST7 is Supervisor of complete CD system such as Servo, Main Processor Communication, DSP control.

Some Tasks of ST7 are as follows:

– Supervisor of all sub blocks

– Initialization of Coefficients for SAC-DSP Digital Servo

– Initialization of parameters of all sub blocks

– Focus search and quick restart

– Coarse Adjustments for Gain(Laser), Offset in Analog front end

– Fine Adjustments for Balance, Offset, Servo Gain in DSP

– Command interpreter and communication with external MPU

– Play & Subcode control, Music search, Random search, Program Play, Scan, Repeat etc.

– One, Ten and Long tracking jump and Pause implementation

– Linear velocity measurement (disc speed)

– Computation of the number of tracks for jump

– Shock proof memory control for data synchronization after shock

ST7 CORE

TDA7522

CS

Address Bus (0:6)

Data Bus (0:7)

IMU

AGU

CD TEXT

4 KBytes

RAM

24 KBytes

ROM

TIMER

Watchdog

CS

CS

CS

CS

Address Bus (0:15)

Data Bus (0:7)

1024

CS

General Purpose I/O

Port A,B

Bytes

RAM

PERIPHERALS