Functional description

TDA7580

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There are built in filters for field strength processing. In order to obtain the maximum

flexibility the field strength processing and noise cancellation, however, are implemented as

software inside the programming DSP, which has to provide control signals for the stages

softmute, stereoblend, and highcut.

8.5

Serial audio interface (SAI)

The two SAI modules have been embedded in such a way great flexibility is available in their

use.

The two modules are fully separate and they each have a receive and a transmit channel, as

well as they can be selected as either master or slave.

The bit clocks and left & right clocks are routed through the pins, so the audio interface can

be chosen to be adapted to a large variety of application.

One SAI transmit channel can have the asynchronous sample rate converter in front, thus

separate different audio rate domains.

Additional feature are:

●

support of 16/24/32 bit word length

●

programmable left/right clock polarity

●

programmable rising/falling edge of the bit clock for data valid

●

programmable data shift direction, MSB or LSB received / transmitted first

8.6

The inter integrated circuit bus is a single bidirectional two wire bus used for efficient inter IC

memory or some other complex function chip. Each of these chips can act as a receiver and

/or transmitter on its functionality.

8.7

Serial peripheral interfaces

SPI modules have separate pin for chip select.

The DSP SPI has a ten 24 bit words deep FIFO for both receive and transmit sections,

which reduces DSP processing overhead even at high data rate.

The serial interface is needed to exchange commands and data over the LAN. During an

SPI transfer, data is transmitted and received simultaneously. A serial clock line

synchronizes shifting and sampling of the information on the two serial data lines. A slave

select line allows individual selection of a slave SPI device.

When an SPI transfer occurs an 8-bit word is shifted out one data pin while another 8-bit

character is simultaneously shifted in a second data pin. The central element in the SPI