> 4.1 | Software Architecture

> The SMTK enables a customer to develop a Java application on a PC and have it be executable on the Java enabled module. The application is then loaded onto the module. The platform comprises:

> • | Java TM Micro Edition (Java METM), which forms the base of the architecture.

> The Java ME TM is provided by SUN Microsystems, http://java.sun.com/javame/. It is specifically designed for embedded systems and has a small memory footprint. The ME uses:
> CLDC 1.1 HI, the connected limited device configuration hot spot implementation.
> IMP-NG, the information module profile 2 nd generation, this is for the most part identical to MIDP 2.0 but without the lcdui package.

> • | Additional Java virtual machine interfaces:

> AT Command API
> File I/O API
> The data flow through these interfaces is shown in Figure 7 and Figure 29.

> • | Memory space for Java programs:

> Flash File System: around 1700k (1200k in XT75)
> RAM: around 400k
> Application code and data share the space in the flash file system and in RAM.

> • | Additional accessible periphery for Java applications

> - | A maximum of ten digital I/O pins usable, for example, as: Output: status LEDs

> - | Input: Emergency Button

> - | One I2C/SPI Interface.

> - | One Digital Analog Converter and two Analog Digital Converters.

> - | Serial interface (RS-232 API): This standard serial interface could be used, for example, with an external GPS device or a current meter. For detailed information see Section 4.2.