ST18952 datasheet(35/67 Pages) STMICROELECTRONICS

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ST18952

SIO

The ST18952 has two synchronous serial input/output (SIO) ports which link to serial devices

such as codecs and to other processors.

The SIO ports work in DMA mode. SIO0 uses channels 0 and 1 of the DMA controller, SIO1

uses channels 2 and 3. The chip must be configured for SIO using the DMAR system register

(”DMAR: DMA management register” on page 44). For SIO port 0, bits 1 and 0 of the DMAR

communication with the outside. For SIO port 1, bits 3 and 2 of the DMAR register must be

reset to inhibit external DMA requests (3 and 2) and to allow SIO port 1 communication with

the outside.

The SIO ports have the following features:

• double-buffered full-duplex operation

• frequency up to D950 input clock (33 Mbps for 66 MHz D950)

• programmable functions

•

word length: 8/16 bits (msb first)

•

up to 8 words per frame

•

frequency prescaler (by 1 or 3) and divider (by 21 to 28)

•

synchronization signal: bit length/word length, delayed/not delayed, active level

•

clock signal: internal/external, active edge

• 4 status flags / 2 enabled interrupt requests

• data transfers between SIO and memories using DMA

ST18952 Datasheet(PDF) 35 Page - STMicroelectronics