Справочник Пользователя для Silicon Laboratories Finland Oy WT12

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/Filter

Combined balun and filter changes the balanced input/output signal of the module to

unbalanced signal of the monopole antenna. The filter is a band pass filter (ISM band).

2.2.5 Matching

Antenna matching components match the antenna to 50 Ohms.

2.2.6 Antenna

The antenna is ACX AT3216 chip antenna.

2.2.7 USB

This is a full speed Universal Serial Bus (USB) interface for communicating with other

compatible digital devices. WT12 acts as a USB peripheral, responding to requests from a
Master host controller such as a PC.

2.2.8 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.

2.2.9 UART

This is a standard Universal Asynchronous Receiver Transmitter (UART) interface for
communicating with other serial devices.

2.2.10 Audio PCM Interface

The audio pulse code modulation (PCM) Interface supports continuous transmission and

reception of PCM encoded audio data over Bluetooth.

2.2.11 Programmable I/O

WT12 has a total of 6 digital programmable I/O terminals. These are controlled by

firmware running on the device.

2.2.12 Reset

This can be used to reset WT12.

2.2.13 802.11 Coexistence Interface

Dedicated hardware is provided to implement a variety of coexistence schemes. Channel
skipping AFH (Adaptive Frequency Hopping), priority signaling, channel signaling and host

passing of channel instructions are all supported. The features are configured in firmware.