The BR105 computer system is a single board computer module. The central component is the BR105 microprocessor. Along with the microprocessor the board module configures 1MB fast access RAM, 2MB Serial Flash Memory, where the user program is downloaded and stored. Once the RESET button is applied the user’s program will be automatically loaded into RAM through Serial Peripheral Interface of the microprocessor, and the system starts to run. Figure 1 shows the major components of BR105 board module.

The BR105 microprocessor has built in five basic IO interfaces: the system timer, the direct input/output signal interface, the asynchronous serial interface, I2C, and the serial peripheral interface (SPI). The SPI interface is dedicated to Serial Flash Memory access in this module. All the basic interfaces are available for access by users through I/O instructions.

It is necessary to mention here that the development kit of BR105 computer system includes C compiler of BR105 microprocessor, assembler of BR105 assembly language, simulator of BR105 instruction set, and download utility for BR105 microprocessor to download user program from PC to Serial Flash Memory. The documentations related to all these parts are specified in different parts. Please refer to the following documents for more details.