Specifications

9. SOFTWARE STACKS

WT32 is supplied with Bluetooth v2.0 + EDR compliant stack firmware, which runs on the

internal RISC microcontroller.

The WT32 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 35: iWRAP Stack

In figure 35 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 through one or more of the physical

interfaces, which are also shown in the figure 35. The most common interfacing is done

through the 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 application code to run on the host processor to control iWRAP

software by using ASCII commands and to develop Bluetooth powered applications.