BCM20705 Datasheet, PDF (29/67 Pages) Cypress Semiconductor – Single-Chip Bluetooth Transceiver and Baseband Processor

BCM20705 Data Sheet
Peripheral Transport Unit
Section 5: Peripheral Transport Unit
This section discusses the PCM, USB, UART, and SPI peripheral interfaces. The BCM20705 has a 1040 byte
transmit and receive fifo, which is large enough to hold the entire payload of the largest EDR BT packet (3-DH5).
PCM Interface
The BCM20705 PCM interface can connect to linear PCM codec devices in master or slave mode. In master
mode, the device generates the PCM_BCLK and PCM_SYNC signals. In slave mode, these signals are
provided by another master on the PCM interface as inputs to the device.
The device supports up to three SCO or eSCO channels through the PCM interface and each channel can be
independently mapped to any available slot in a frame.
The host can adjust the PCM interface configuration using vendor-specific HCI commands or it can be setup in
the configuration file.
System Diagram
Figure 5 shows options for connecting the device to a PCM codec device as a master or a slave.
Figure 5: PCM Interface with Linear PCM Codec
PCM Codec
(Master)
PCM_IN
PCM_OUT
PCM_BCLK
PCM_SYNC
PCM Interface Slave Mode
BCM20705
(Slave)
PCM Codec
(Slave)
PCM_IN
PCM_OUT
PCM_BCLK
PCM_SYNC
PCM Interface Master Mode
BCM20705
(Master)
PCM Codec
(Hybrid)
PCM_IN
PCM_OUT
PCM_BCLK
PCM_SYNC
PCM Interface Hybrid Mode
BCM20705
(Hybrid)
Broadcom®
Bluetooth Transceiver and Baseband Processor
November 13, 2014 • MCS20705-DS104-R
Page 28
BROADCOM CONFIDENTIAL