TDA7522 Datasheet, PDF (15/23 Pages) STMicroelectronics – Digital Servo & Decoder

Figure 3. ST7 Interface Overview
TDA7522
General Purpose I/O
Port A,B
CS
CS
IMU
AGU
ST7 CORE
CS
Address Bus (0:6)
Data Bus (0:7)
CS
CS
CS
Address Bus (0:15)
Data Bus (0:7)
1024
Bytes
RAM
TIMER
Watchdog
CD TEXT
4 KBytes
RAM
24 KBytes
ROM
TDA7522
PERIPHERALS
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
15/23