BCM20707 Preliminary Data Sheet
Microprocessor Unit
Microprocessor Unit
The BCM20707 microprocessor unit runs software from the link control (LC) layer up to the host controller
interface (HCI). The microprocessor is based on the Cortex-M3 32-bit RISC processor with embedded ICE-RT
debug and JTAG interface units. The microprocessor also includes 848 KB of ROM memory for program storage
and boot ROM, 352 KB of RAM for data scratch-pad, and patch RAM code.
The internal boot ROM provides flexibility during power-on reset to enable the same device to be used in various
configurations. At power-up, the lower layer protocol stack is executed from the internal ROM.
External patches can be applied to the ROM-based firmware to provide flexibility for bug fixes and features
additions. These patches can be downloaded using external NVRAM. The device can also support the
integration of user applications and profiles using an external serial flash memory.
NVRAM Configuration Data and Storage
NVRAM contains configuration information about the customer application, including the following:
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Fractional-N information
BD_ADDR
UART baud rate
SDP service record
File system information used for code, code patches, or data. The BCM20707 can use SPI Flash or I2C
EEPROM/serial flash for NVRAM storage.
One-Time Programmable Memory
The BCM20707 includes 2 Kbytes of one-time programmable (OTP) memory allow manufacturing
customization and to avoid the need for an on-board NVRAM. If customization is not required, then the OTP
does not need to be programmed. Whether the OTP is programmed or not, to save power it is disabled when
the boot process is complete. The OTP is designed to store a minimal amount of information. Aside from OTP
data, most user configuration information will be downloaded to RAM after the BCM20707 boots and is ready
for host transport communication.
Note: The OTP is disabled internally for the 36-Pin WLBGA package.
The OTP contents are limited to:
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Parameters required prior to downloading the user configuration to RAM.
Parameters unique to each part and each customer (for example, the Bluetooth device address and/or the
software license key).
Broadcom®
Bluetooth SoC
May 27, 2016 • 20707-DS206-R
Page 12
BROADCOM CONFIDENTIAL
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