9/23

STLC2500

output of the band pass filter is amplified by a VGA to the optimal input range for the A/D converter. Further

channel filtering is done in the digital part. The digital part demodulates the GFSK coded bit stream by

evaluating the phase information in the digital I and Q signals. RSSI data is extracted. Overall automatic

gain amplification in the receive path is controlled digitally. The RC time constants for the analogue filters

are automatically calibrated on chip.

6.3

PLL

The on-chip VCO is part of a PLL. The tank resonator circuitry for the VCO is completely integrated without need

of external components. Variations in the VCO centre frequency are calibrated out automatically.

6.4

Baseband 1.1 Features

The baseband is based on Ericsson Licensing Technology Baseband Core (EBC) and it is compliant with

the Bluetooth specification 1.1:

– Point to multipoint (up to 7 Slaves)

– Asynchronous Connection Less (ACL) link support giving data rates up to 721 kbps

– Synchronous Connection Oriented (SCO) link with support for 2 voice channels over the air interface

– Flexible voice format to Host and over the air (CVSD, PCM 13/16 bits, A-law,

µ-law)

– HW support for packet types: DM1, 3, 5; DH1, 3, 5; HV1, 3; DV

– Scatternet capabilities (Master in one piconet and Slave in the other one; Slave in two piconets). All

scatternet v.1.1 errata supported

– Ciphering support up to 128 bits key

– Paging modes R0, R1, R2

– Channel Quality Driven Data Rate

– Full Bluetooth software stack available

– Low-level link controller

6.5

Baseband 1.2 Features

The baseband part is also compliant with the Bluetooth specification 1.2:

– Adaptive Frequency Hopping (AFH): hopping kernel, channel assessment as Master and as Slave

– Faster Connection: Interlaced scan for Page and Inquiry scan, answer FHS at first reception, RSSI used

to limit range

– Extended SCO (eSCO) links: supports EV3 and EV5 packets

– QoS Flush

– Synchronization: BT clocks are available at HCI level for synchronization of parallel applications on dif-

ferent Slaves

– L2CAP Flow & Error control

– LMP improvements

– LMP SCO handling

– Parameter Ranges update

6.5.1

V1.2 detailed functionality - Extended SCO

User Perspective - Extended SCO

This function gives improved voice quality since it enables the possibility to retransmit lost or corrupted

voice packets in both directions.

Technical perspective - Extended SCO

eSCO incorporates CRC, negotiable data rate, negotiable retransmission window and multi-slot packets.

Retransmission of lost or corrupted packets during the retransmission window guarantees on-time deliv-

ery.