User's Manual

Bluegiga Technologies Oy
Page 24 of 52
12 Memory Management
12.1 Memory Management Unit
The MMU provides a number of dynamically allocated ring buffers that hold the data that is in transit between
the host and the air. The dynamic allocation of memory ensures efficient use of the available RAM and is
performed by a hardware MMU to minimize the overheads on the processor during data/voice transfers.
12.2 System RAM
56KB of integrated RAM supports the RISC MCU and is shared between the ring buffers for holding
voice/data for each active connection and the general-purpose memory required by the Bluetooth stack.
12.3 Internal ROM Memory (5Mb)
5Mb of internal ROM memory is available on BT111. This memory is provided for system firmware, storing
BT111 settings and program code.
12.4 Internal EEPROM
32Kb internal EEPROM is available on BT111 to store device specific configuration information (PS Keys)
such as Bluetooth address, USB descriptors, PCM configuration and maximum TX power. The internal
EEPROM is powered from VDD_PADS. The minimum supply voltage writing the EEPROM is 2.7V and the
minimum supply voltage for reading the EEPROM is 1.7V.