User's Manual

BT860
Datasheet
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8.3.4. Wideband Speech Support
When the host encodes Wideband Speech (WBS) packets in transparent mode, the encoded packets are
transferred over the PCM bus for an eSCO voice connection. In this mode, the PCM bus is typically configured in
master mode for a 4 kHz sync rate with 16-bit samples, resulting in a 64 Kbps bit rate. The BT860 also supports
slave transparent mode using a proprietary rate-matching scheme. In SBC-code mode, linear 16-bit data at 16
kHz (256Kbps rate) is transferred over the PCM bus.
8.3.5. Multiplexed Bluetooth Over PCM
Bluetooth supports multiple audio streams within the Bluetooth channel and both 16 kHz and 8 kHz streams can
be multiplexed. This mode of operation is only supported when the Bluetooth host is the master. Figure7 shows
the operation of the multiplexed transport with three simultaneous SCO connections. To accommodate
additional SCO channels, the transport clock speed is increased. To change between modes of operation, the
transport must be halted and restarted in the new configuration.
Figure 7: Functional Multiples Data diagram
8.3.6. Burst PCM Mode
In this mode of operation, the PCM bus runs at a significantly higher rate of operation to allow the host to duty
cycle its operation and save current. In this mode of operation, the PCM bus can operate at a rate of up to 24
MHz. This mode of operation is initiated with an HCI command from the host.
Figure 8 and Table 15 shows PCM Burst mode timing diagram and specifications for the receive-only mode of
short-frame sync.