BCM20730 Data Sheet
Microprocessor Unit
Microprocessor Unit
The BCM20730 microprocessor unit (µPU) executes software from the link control (LC) layer up to the
application layer components that ensure adherence to the Bluetooth Human Interface Device (HID) profile
and Audio/Video Remote Control Profile (AVRCP). The microprocessor is based on an ARM Cortex™-M3, 32-bit
RISC processor with embedded ICE-RT debug and JTAG interface units. The µPU has 320 KB of ROM for program
storage and boot-up, 60 KB of RAM for scratch-pad data, and patch RAM code.
The internal boot ROM provides power-on reset flexibility, which enables the same device to be used in
different HID applications with an external serial EEPROM or with an external serial flash memory. At power-
up, the lowest layer of the protocol stack is executed from the internal ROM memory.
External patches may be applied to the ROM-based firmware to provide flexibility for bug fixes and feature
additions. The device can also support the integration of user applications.
EEPROM Interface
The BCM20730 provides a Broadcom Serial Control (BSC) master interface. The BSC is programmed by the CPU
to generate four types of BSC bus transfers: read-only, write-only, combined read/write, and combined write/
2
read. BSC supports both low-speed and fast mode devices. The BSC is compatible with a Philips® (now NXP) I C
2
slave device, except that master arbitration (multiple I C masters contending for the bus) is not supported.
The EEPROM can contain customer application configuration information including: application code,
configuration data, patches, pairing information, BD_ADDR, baud rate, SDP service record, and file system
information used for code.
Native support for the Microchip® 24LC128, Microchip 24AA128, and ST Micro® M24128-BR is included.
Serial Flash Interface
The BCM20730 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.
Devices natively supported include the following:
• Atmel® AT25BCM512B
• MXIC® MX25V512ZUI-20G
BROADCOM
®
September 9, 2013 • 20730-DS108-R
Page 21
BROADCOM CONFIDENTIAL
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