BCM89071A1CUBXGT Datasheet, PDF (32/69 Pages) Cypress Semiconductor – Single-Chip Automotive Grade Bluetooth Transceiver and Baseband Processor

BCM89071 Data Sheet
HCI Transport Detection Configuration
Data Formatting
The device can be configured to generate and accept several different data formats. The device uses 13 of the
16 bits in each PCM frame. The location and order of these 13 bits is configurable to support various data
formats on the PCM interface. The remaining three bits are ignored on the input, and may be filled with zeros,
ones, a sign bit, or a programmed value on the output. The default format is 13-bit two’s complement data, left
justified, and clocked most significant bit first.
HCI Transport Detection Configuration
The BCM89071 supports the following interface types for the HCI transport from the host:
• UART (H4 and H5)
• SPI
Only one host interface can be active at a time. The firmware performs a transport detect function at boot-time
to determine which host is the active transport. It can auto-detect the UART interface, but the SPI interface must
be selected by strapping the SCL pin to 0.
The complete algorithm is summarized as follows:
1. Determine if SCL is pulled low. If it is, select SPI as HCI host transport.
2. Determine if any local NVRAM contains a valid configuration file. If it does and a transport configuration entry
is present, select the active transport according to entry, and then exit the transport detection routine.
3. Search for CTS_N = 0 on the UART interface. If it is present, select UART.
4. Repeat Step 3 until transport is determined.
Broadcom^®
April 16, 2015 • 89071-DS106-R
Baseband Transceiver and Baseband Processor
Page 31