User's Manual

9. SOFTWARE STACKS

WT11 is supplied with Bluetooth v2.0 + EDR compliant stack firmware, which runs on the

internal RISC microcontroller.

The WT11 software architecture allows Bluetooth processing and the application program

to be shared in different ways between the internal RISC microcontroller and an external

host processor (if any). The upper layers of the Bluetooth stack (above HCI) can be run

either on-chip or on the host processor.

9.1 iWRAP Stack

PCM I/O

Host I/O

Radio

48kB RAM Baseband MCU

HCI

L2CAP

RFCOMM SDP

iWRAP

UART

Host

I/O

PCM

Figure 8: WRAP THOR VM Stack

In figure above, the iWRAP software solution is described. In this version of the stack

firmware shown no host processor is required to run the Bluetooth protocol stack. All

software layers, including application software, run on the internal RISC processor in a

protected user software execution environment known as a Virtual Machine (VM).

The host processor interfaces to iWRAP software via one or more of the physical interfaces

which are also shown in the figure above. The most common interfacing is done via UART

interface using the ASCII commands supported by the iWRAP software. With these ASCII

commands the user can access Bluetooth functionality without paying any attention to the

complexity which lies in the Bluetooth protocol stack.

The user may write applications code to run on the host processor to control iWRAP

software with ASCII commands and to develop Bluetooth powered applications.