User's Manual

7
2.2.2 Crystal
The crystal oscillates at 26MHz.
2.2.3 Flash
Flash memory is used for storing the Bluetooth protocol stack and Virtual Machine
applications. It can also to the optional external RAM for memory intensive applications.
2.2.4 Balun
Balun changes the balanced input/output signal of the module to unbalanced signal of the
monopole antenna.
2.2.5 Power amplifier
Power amplifier is used to increase the output power to a level required by class 1
specification.
2.2.6 Switch
Switch is used to separate transmission and receiver modes.
2.2.7 Matching
Antenna matching components match the antenna to 50 Ohms and also selects between
chip antenna and UFL connector.
2.2.8 Antenna
The antenna is ACX AT3216 chip antenna.
2.2.9 U.FL
This is a standard U.FL male connector for external antenna possibility.
2.2.10 USB
This is a full speed Universal Serial Bus (USB) interface for communicating with other
compatible digital devices. WT11 acts as a USB peripheral, responding to requests from a
Master host controller such as a PC.
2.2.11 Synchronous Serial Interface
This is a synchronous serial port interface (SPI) for interfacing with other digital devices.
The SPI port can be used for system debugging. It can also be used for programming the
Flash memory.
2.2.12 UART
This is a standard Universal Asynchronous Receiver Transmitter (UART) interface for
communicating with other serial devices.
2.2.13 Audio PCM Interface
The audio pulse code modulation (PCM) Interface supports continuous transmission and
reception of PCM encoded audio data over Bluetooth.