BCM20705 Datasheet, PDF (24/67 Pages) Cypress Semiconductor – Single-Chip Bluetooth Transceiver and Baseband Processor

BCM20705 Data Sheet
Serial Enhanced Coexistence Interface
SECI Advantages
The advantages of the SECI over the legacy 3-wire coexistence interface are:
• Only two wires are required: SECI_IN and SECI_OUT.
• Up to 48-bits of coexistence data can be exchanged.
Previous Broadcom standalone Bluetooth devices such as the BCM2070 supported only a 3-wire or 4-wire
coexistence interface. Previous Broadcom WLAN and Bluetooth combination devices such as the BCM4325,
BCM4329, and BCM4330 support an internal parallel enhanced coexistence interface for more efficient WLAN
and Bluetooth information exchange. The SECI allows enhanced coexistence information to be passed to a
companion Broadcom WLAN chip through a serial interface using fewer I/O than the 3-wire coexistence
scheme.
The 48-bits of the SECI significantly enhance WLAN and Bluetooth coexistence by sharing such information as
frequencies used and radio usage times. The exact contents of the SECI are Broadcom confidential.
SECI I/O
The BCM20705 does not have dedicated SECI_IN or SECI_OUT pins, but the two pin functions can be mapped
to the following digital I/O: the UART, GPIO, SPI Master (or BSC), PCM, and COEX pins. Pin function mapping
is controlled by the config file that is either stored in NVRAM or downloaded directly into on-chip RAM from the
host.
Broadcom®
Bluetooth Transceiver and Baseband Processor
November 13, 2014 • MCS20705-DS104-R
Page 23
BROADCOM CONFIDENTIAL