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7. CIRCUIT OPERATION (HANDSET)
BLOCK DIAGRAM BASEBAND SECTION (HANDSET)
7.1. THE BASE BAND SECTION
7.1.1. INTRODUCTION
The base-band section consists of a base-band integrated circuit (BBIC), a Flash PROM, an
EEPROM, an LCD Display, a Microphone, an Earpiece, and power supply/battery management
circuits.
7.1.2. THE BASE-BAND INTEGRATED CIRCUIT (BBIC)
The PMB6723 (IC1) is a CMOS device designed to handle all the audio, signal and data
processing needed in a DECT handset. It contains a "burst mode controller" which takes care of
DECT specific physical layer and radio section control. It also contains an ADPCM codec filter
used for speech encoding and decoding in the DSP section, a general purpose microcontroller,
various other ADC's, DAC's, timers and power control circuitry.
The BBIC interfaces to its external PROM (IC3) via a data/address/control bus. It connects to the
EEPROM (IC2) via a serial interface (SDA and SDC). This serial interface is also used during
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