TDA7505 Datasheet, PDF (6/38 Pages) STMicroelectronics – Car radio DSP for advanced signal processing

Overview
1
Overview
TDA7505
The TDA7505 integrates two 75 MIPS DSP cores. One core is used for stereo decoding,
noise blanking, weak signal processing, Dolby B, music search and MP3 decoding. The
second core is used for audio and sound processing and Echo & Noise cancellation. All
functions are realized in SW and thus are flexible on customer request.
The device may be controlled by a main micro through either SPI or I²C interface. Through
the same pins, but with separate device address (I²C) respectively separate chip select line
(SPI) the main micro may communicate with the DSP or with the RDS block.
An additional SPI is available allowing a separate communication (e.g. to a display micro).
The DSP cores are integrated with their associated data and program memories.
DSP0 is declared as master. Its associated peripherals and interfaces are: I²C, SPI1
(Master SPI), SPI2 (Display SPI), Serial Audio Interface (SAI), PLL Oscillator, External
Memory Interface (EMI), General Purpose I/O ports (DSP0 GPIO[0..11]), RDS filter and D/A
converters.
DSP1 is declared as Co-DSP. Its associated peripherals and interfaces are: A/D converters,
SPDIF, Sample Rate Converter (SRC) and General Purpose I/O ports (DSP1 GPIO[0..11]).
Both DSP´s are identical (ST Orpheus core, 75 MHz clock). Only the peripherals and
memory configurations are different. The internal communication takes place through a bi-
directional 24/10-word exchange interface (XCHG) with complex flag and interrupts
capability.
The Radio Data System (RDS, respectively RBDS) function is realized via dedicated
hardware. It may run fully autonomous without SW intervention. Thus an efficient
background mode as well as a low current standby mode is possible. The RDS input is
connected to the A/D converter to receive the FM multiplex signal (MPX) automatically. Its
output may be configured to I²C or SPI format. The pins are shared with the I²C and SPI1 of
DSP0.
The device is equipped with a debug and test interface. It allows the SW development with a
100% compatible emulation system.
All functions, except RDS, are implemented in SW. Thus, the device may be adapted to
customers´ requirements. This implies the variable implementation of SW modules
developed by the customer, ST and third parties. This flexibility also allows the usage for
applications others than car radios, e.g.: Boosters.
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