1. WAVECOM©2005. All rights reserved 1 PROTECTIONS Embedded Software Architecture AT commands Parser Customer Application written in Standard ANSI C Wavecom Wireless CPU Open AT ® FW: Seamlessly brings the Wireless Connectivity Application Development Layer Library: This library provides a set of high level of APIs for easy application development Open AT ® Plug-In Library: Pre-packaged libraries such as TCP/IP and Internet Protocols Plug Ins may be used to increase the set of service provided by Open AT ® OS TCP/IP – Internet – Security – C-GPS C-AGPS – C-Bluetooth - … Task1 … Interrupt Handler Memory Access Protection Watchdog RTOS Open AT Real Time: Guarantied Response Time to interruption whatever the GSM State (IDLE Mode, Call, Data Transfer, Network search…) Open AT ® Firmware (GSM/GPRS/EDGE stack) Plug-Ins (Lib) TaskN Protections: Against Rogue Memory access and application dead end lock

2. WAVECOM©2005. All rights reserved 2  Interruption handler to manage the External Interruptions (up to 9 Interruption pins), Hardware Timer and DSP interruptions with Improved latency  Access to 1 high granularity internal timer (with 4 Comparable values): Hardware Timer.  Wavecom provides the Open AT ® developers with access to the lowest hardware resources through Low Levels Interrupt Handlers: GUARANTIED REACTION TIME. Real Time Open AT ® OS

3. WAVECOM©2005. All rights reserved 3 Open AT ® Application Tasks “ First era ” One single task Open AT ® OS Real Time Architecture GSM Stack Interrupt Handler Open AT ® Interrupt Handler Level 1 (Timer + External) Open AT ® Interrupt Task Handler (Timer + External) GSM AT Commands Task GSM IDLE Task GSM Stack Tasks L3 L2 L1 PRIORITY LEVEL Task Domain Interrupt Domain Open AT ® Application Task RTOS Step1 One single task Open AT ® Application Tasks RTOS Step2 Multiple tasks : T1 … TN Open AT ® Interrupt Handler Level 0 (Timer + External) REACTION TIME < 20 µs < 600 µs ~ 10 ms Indicative Response Time Guarantied Response Time

4. WAVECOM©2005. All rights reserved 4 Open AT ® Application Tasks “ First era ” One single task Open AT ® OS Real Time Architecture GSM Stack Interrupt Handler Open AT ® Interrupt Handler Level 1 (Timer + External) Open AT ® Interrupt Task Handler (Timer + External) GSM AT Commands Task GSM IDLE Task GSM Stack Tasks L3 L2 L1 Open AT ® Application Task RTOS Step1 One single task Open AT ® Application Tasks RTOS Step2 Multiple tasks : T1 … TN Open AT ® Interrupt Handler Level 0 (Timer + External) Open AT Application tasks: This is the core of the customer application. It is design to execute high level processes that are not time critical. Open AT Interrupt Task: This Interrupt tasks has been design to perform long or resources demanding operation such as complex calculation or value acquisition report creation and storage in Flash Memory. This operations would have to be performed asynchronously and would not be time critical. Open AT Interrupt Handler: This Interrupt handler is the second highest or Highest priority process on the platform. It is designed to perform asynchronous time critical operations. Its code would start being executed within 1 ms (Level 1) or 10µs (Level0) upon interruption (HW timer or external) detection. It is design to perform very short operations such as value acquisition and storage in RAM (for ex in a circular buffer)

5. WAVECOM©2005. All rights reserved 5 CUS IRQ IRQ Processing Latency at Level 1 CUS IRQ EXT/Timer IT Request: Executed without Delay EXT / TIMER IRQ CUS IRQ EXT/Timer IT Request: Executed with Delay due to Lowest Priority EXT/Timer IT Request: Execution frozen due to GSM Radio Request GSM Radio Request: Highest priority 4,615 ms GSM Up to 600 µs GSM IRQ GSM Up to 600 µs GSM IRQ GSM Up to 600 µs GSM IRQ EXT / TIMER IRQ IRQ = Interruption TIME

6. WAVECOM©2005. All rights reserved 6 CUS IRQ IRQ Processing Latency at Level 0 CUS IRQ EXT/Timer IRQ Request: Executed without Delay EXT / TIMER IRQ CUS IRQ EXT/Timer IRQ Request: Executed without Delay EXT/Timer IRQ Request: Execution will be processed until finished GSM Radio Request: Executed Without Delay 4,615 ms GSM GSM IRQ GSM GSM IRQ EXT / TIMER IRQ TIME GSM GSM Radio Request: Executed Frozen GSM Radio Request: Executed Delayed Latency for Code Processing: Platform Scheduling Time: <20 µs

7. WAVECOM©2005. All rights reserved 7 Hardware timer set to 20ms and one comparable value set at 10ms Open AT ® RTOS Demo  The Open AT application is generating a cyclic signal on a GPIO Period: 20ms High State: 10ms Generated Signal: Low level handler: Best and worst case at the oscilloscope: Unknown state for 1ms due to latency time for IT processing Unknown state for 2ms due to Oscilloscope sync on first rising edge Compared value expires: 10ms Hardware Timer expires at 20ms

8. WAVECOM©2005. All rights reserved 8 Open AT ® Application Development  Open AT® IDE: Integrated Development Environment – Built on Eclipse – Eclipse: v3.3 – CDT: (C/C++ Development Tools) v4.0  All Wavecom Tools Are CDT Plug Ins: – Downloader – Terminal Emulator – Target Monitoring Tool – Remote Task Environment  New Tools: – Supervisor – JTAG + GDB