BCM20713A1KUBXGT Datasheet, PDF (28/65 Pages) Cypress Semiconductor – Single-Chip Bluetooth Transceiver and Baseband Processor

BCM20713 Preliminary Data Sheet
PCM Interface
Slot Mapping
The device supports up to three simultaneous, full-duplex SCO or eSCO channels. These channels are time-
multiplexed onto the PCM interface using a time slotting scheme based on the audio sampling rate, as described
in Table 2.
Table 2: PCM Interface Time Slotting Scheme
Audio Sample Rate Time Slotting Scheme
8 kHz
The number of slots depends on the selected interface rate, as follows:
Interface rate Slot
128
1
256
2
512
4
1024
8
2048
16
16 kHz
The number of slots depends on the selected interface rate, as follows:
Interface rate Slot
256
1
512
2
1024
4
2048
8
Transmit and receive PCM data from an SCO channel is always mapped to the same slot. The PCM data output
driver tristates its output on unused slots to allow other devices to share the same PCM interface signals. The
data output driver tristates its output after the falling edge of the PCM clock during the last bit of the slot.
Wideband Speech
The BCM20713 provides support for wideband speech (WBS) in two ways:
• Transparent mode: The host encodes WBS packets and the encoded packets are transferred over the
PCM bus for SCO or eSCO voice connections. In Transparent 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.
• On-chip SmartAudio^® technology: The BCM20713 can perform Subband-Codec (SBC) encoding and
decoding of linear 16 bits at 16 kHz (256 kbps rate) transferred over the PCM bus.
Frame Synchronization
The device supports both short and long frame synchronization types in both master and slave configurations.
In short frame synchronization mode, the frame synchronization signal is an active-high pulse at the 8 kHz audio
frame rate (which is a single bit period in width) and synchronized to the rising edge of the bit clock. The PCM
slave expects PCM_SYNC to be high on the falling edge of the bit clock and the first bit of the first slot to start
at the next rising edge of the clock. In the long frame synchronization mode, the frame synchronization signal
is an active-high pulse at the 8 kHz audio frame rate. However, the duration is 3-bit periods and the pulse starts
coincident with the first bit of the first slot.
Broadcom^®
December 21, 2015 • 20713-DS102-R
Single-Chip Bluetooth Transceiver and Baseband Processor
Page 27
BROADCOM CONFIDENTIAL