Copyright 1998 National Semiconductor Corp.

1

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SC14422

Complete Baseband Processor for DECT Base Stations

General Description

Preliminary document version 1.1.

The SC14422 is a 3.0 Volt CMOS IC optimized to handle

all the audio, signal and data processing needed within a

DECT basestation. An ADPCM transcoder, a very low

power CODEC and Analog Frontend are integrated. Di-

rect connections towards analog or ISDN line interface.

The SC14422 is designed to be compatible with many

radio interfaces. A dedicated TDMA controller handles all

physical layer slot formats and radio control.

The

integrated

National

Semiconductor’s

standard

CR16A processor core with external Program memory

(Flash or ROM) takes care of all the higher protocol stack.

Programmable I/O ports can be configured as chip selects

for I/O expanders, Serial Flash memory, interrupt source

or I/O. A digital serial interface can be configured to inter-

face to many codecs and ISDN devices with

linear or transparent data formats.

Features

s Integrated DECT base band transceiver optimized for

GAP base stations according to ETS 300 175-2, 175-3

& 175-8.

s 3.0 to 5.5 Volt operating voltage.

essor with In System Emulation (ISE) mode.

s 2k + 4kbyte Data Memory.

s Two full duplex 32 kbits/sec ADPCM transcoder.

s 14-bit linear CODEC with programmable gain

s Serial interface to external codecs and ISDN interface

circuits.

s Echo canceller, two echo suppressors, DTMF genera-

tor, sidetone and artificial echo loss.

s On-chip gaussian Modulator.

s Peak hold ADC for RSSI measurement

s Three input 8 bit successive approximation ADC.

s On board programmable Dedicated Instruction Proces-

sor (DIP) for all TDMA based events.

s Protected and unprotected half, full and double slot B-

fields D00, D08, D32 and D80

s Standard DECT encryption with different keys for

different MAC-connections.

s 6 MAC connections can be handled simultaneously.

s Flexible three wire interface to radio front synthesizer.

s Three general purpose I/O ports with programmable in-

terrupts.

s General purpose full duplex UART.

s Two general purpose timers and watchdog timer.

s Programmable chip selects to 8 bit wide ROM, SRAM

NAND Flash Memory and I/O expanders.

s Capture timer for frequency measurement for e.g. me-

tering, ringing and call progress tone detection.

s 100 pin TQFP-100 package.

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System Diagram

SC14401

SC14402

SC14401

4220030

SC14402

SC14402

SC14422

PSTN

ISDN

ISDN or

PSTN

Interface

PRELIMINARY

March 1998