AN-1699| Application Note

LMX9838 Software Users Guide

National Semiconductor Application Note 1699 Sebastien Mathieu March 17, 2008

1.0 Introduction
The National Semiconductor LMX9838 Bluetooth Serial Port module is a fully integrated Bluetooth 2.0 baseband controller, 2.4 GHz radio, crystal, antenna, LDO and discrets combined to form a complete small form factor (10 mm x17 mm x 2.0 mm) Bluetooth node. All hardware and firmware is included to provide a complete solution from antenna through the complete lower and upper layers of the Bluetooth stack, up to the application including the Generic Access Profile (GAP), the Service Discovery Application Profile (SDAP), and the Serial Port Profile (SPP). The module includes a configurable service database to fulfill service requests for additional profiles on the host. Moreover, the LMX9838 is pre-qualified as a Bluetooth subsytem. Conformance testing through the Bluetooth qualification program enables a short time to market after system integration by ensuring a high probability of compliance and interoperability. Based on National's CompactRISC 16-bit processor architecture and Digital Smart Radio technolog
y, the LMX9838 is optimized to handle the data and link management processing requirements of a Bluetooth node. The on-chip memory, ROM and Patch RAM, are optimized for lowest cost and risk, allowing the correction of small firmware errors by the patch mechanism. The module offers an automatic slave mode without any configuration necessary from an external host. Additionally it offers a command set for hardware configuration and full bluetooth operation over SPP. This document is a reference for implementing the LMX9838 module into a system. A getting started session gives a very detailed entry point for starting development. The advance usage section describes all features and configuration parameters in detail and gives example for using the LMX9838 as active bluetooth node. Finally all commands and events are listed and explained in the command section. IMPORTANT: Please also always check for Release Notes for possible errors and software workarounds for the firmware. This document is based on: TABLE 1. L
MX9838 Information Item Hardware Firmware Actual Firmware Release SimplyBlueCommander Version LMX9838 V0212 or later V0212 1.6.0.1

2.0 LMX9838 General Setup
2.1 SYSTEM OVERVIEW The LMX9838 is intended to be an add-on module to an existing microcontroller. In this function it either appears as cable like interface for the UART or can also be controlled with a simple application on the external microcontroller to establish links itself. The LMX9838 includes the complete bluetooth stack including the following protocol layers: Link Controller Link Manager L2CAP (Logic Link Control and Adaptation) RFCOMM SDP (Service Discovery Protocol) An on-chip application together with those protocol layers offers the following profiles: GAP (Generic Application Profile) SDAP (Service Discovery Application Profile) SPP (Serial Port Profile) The application manages all profile related interactions to the stack but also offers a simplified command interface over the UART. The interface is used for configuring the device, setting up the link and receiving events from the module. The interface can handle either packaged data transmission for multipoint support or is
able to handle RAW data by setting it into a transparent UART mode. The firmware can also accept or establish synchronous links (SCO) to transmit audio data. Once the link has been established the firmware routes the synchronous data to and from the PCM interface, using predefined driver settings. No further host action is required.

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FIGURE 1. LMX9838 Firmware Implementation
Bluetooth is a registered trademark of Bluetooth SIG, Inc. and is used under license by National Semiconductor Corporation. CompactRISC is a registered trademark of National Semiconductor Corporation.

2008 National Semiconductor Corporation

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