BCM20705 Datasheet, PDF (26/67 Pages) Cypress Semiconductor – Single-Chip Bluetooth Transceiver and Baseband Processor

BCM20705 Data Sheet
NVRAM Configuration Data and Storage
NVRAM Configuration Data and Storage
Serial Interface
The BCM20705 includes an SPI master controller that can be used to access serial flash memory. The SPI
master contains an AHB slave interface, transmit and receive FIFOs, and the SPI core PHY logic. Data is
transferred to and from the module by the system CPU. DMA operation is not supported.
The BCM20705 supports serial flash vendors Atmel®, MXIC, and Numonyx™. The most commonly used parts
from two of these vendors are:
• AT25BCM512B, manufactured by Atmel
• MX25V512ZUI-20G, manufactured by MXIC
EEPROM
The BCM20705 includes a Broadcom Serial Control (BSC) master interface. The BSC interface supports low-
speed and fast mode devices and is compatible with I²C slave devices. Multiple I²C master devices and flexible
wait state insertion by the master interface or slave devices are not supported. The BCM20705 provides 400
kHz, full speed clock support.
The BSC interface is programmed by the CPU to generate the following BSC transfer types on the bus:
• Read-only
• Write-only
• Combined read/write
• Combined write-read
NVRAM may contain configuration information about the customer application, including the following:
• Fractional-N information
• BD_ADDR
• UART baud rate
• USB enumeration information
• SDP service record
• File system information used for code, code patches, or data
External Reset
The BCM20705 has an integrated power-on reset circuit which completely resets all circuits to a known power
on state. This action can also be driven by an external reset signal, which can be used to externally control the
device, forcing it into a power-on reset state. The RST_N signal input is an active-low signal for all versions of
the BCM20705. The BCM20705 requires an external pull-up resistor on the RST_N input. Alternatively, the
RST_N input can be connected to REG_EN or driven directly by a host GPIO.
Broadcom®
Bluetooth Transceiver and Baseband Processor
November 13, 2014 • MCS20705-DS104-R
Page 25
BROADCOM CONFIDENTIAL