BCM4325
Preliminary Data Sheet
6/30/09
Section 5: Bluetooth Baseband Core
The Bluetooth Baseband Core (BBC) implements all of the time critical functions required for high performance Bluetooth
operation. The BBC manages the buffering, segmentation, and routing of data for all connections. It also buffers data that
passes through it, handles data flow control, schedules SCO/ACL TX/RX transactions, monitors Bluetooth slot usage,
optimally segments and packages data into baseband packets, manages connection status indicators, and composes and
decodes HCI packets. In addition to these functions, it independently handles HCI event types, and HCI command types.
The following transmit and receive functions are also implemented in the BBC hardware to increase reliability and security
of the TX/RX data before sending over the air:
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Symbol timing recovery, data deframing, forward error correction (FEC), header error control (HEC), cyclic redundancy
check (CRC), data decryption, and data dewhitening in the receiver.
•
Data framing, FEC generation, HEC generation, CRC generation, key generation, data encryption, and data whitening
in the transmitter.
BLUETOOTH 2.1 AND 3.0 FEATURES
The BBC supports the following Bluetooth 2.1 features:
•
•
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Extended Inquiry Response (EIR) Shortens the time to retrieve device name, specific profile and mode.
Encryption Pause Resume (EPR)
Sniff Subrating (SSR)
Enables the use of Bluetooth technology in a much more secure environment.
Optimizes power consumption for low duty cycle asymmetrical data flow, which
subsequently extends battery life.
•
•
Simple Pairing (SP)
Reduces the number of steps with minimal or no user interaction when connecting
two devices.
Link Supervision Timeout (LST)
In addition, the BBC is compliant with the Bluetooth Core specification 3.0 + HS when combined with Bluetooth 3.0 + HS
qualified host software—including Alternate MAC/PHY, read encryption key size, enhanced power control, and unicast
connectionless data.
FREQUENCY HOPPING GENERATOR
The frequency hopping sequence generator selects the correct hopping channel number depending on the link controller
state, Bluetooth clock, and the device address.
LINK CONTROL LAYER
The link control layer is part of the Bluetooth link control functions that are implemented in dedicated logic in the Link Control
Unit (LCU). This layer consists of the command controller that takes commands from the software and other controllers that
are either activated or configured by the command controller to perform the link control tasks.
Broadcom Corporation
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Bluetooth Baseband Core
Document 4325-DS04-R
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