| American Altera Company developed embedded processor Nios II. Designers can easily use SOPC Builder system development tool to construct system based on processor. According to own request, designers can configure Nios â…¡ soft nucleus, Avalon bus and peripheral interface system that reflects the SOPC technology design thought facing user and application. The application of the integrated development platform and auxiliary development tools accelerates the developing speed of the SOPC design and verification, also has extensive value and profound significance for design and application of embedded system.For its characteristics of small volume, high storage capacity, removable and nonvolatile storage space, low price, and so on, SD memory card is widely applied in cell phone, digital camera, MP3player, and so on. It also can achieve the goal of extending embeded system memory.The design for SD card read and write based on the SOPC contains hardware and software pats. In hardware design part, the main development tools are Quartus II and the SOPC Builder. According to the requirement of system hardware configuration, we can import the module in integrated library such as Nios II CPU. Tristate Bridge, flash, sram, timer, jtag_uart, sd_clk, sd_cmd, sd_dat, sd_dat3and so on to the SOPC Builder.In software design part, the main development tool is Nios II integrate design environment. In it, we realize the software design for reading and writing SD card in the SPI mode. Based on the above design, we also realize the software design of creating and reading and writing files in the SD card according to FAT16file format.Result proves that, this system has achieved the base reading and writing function and strong manipulation. Beside, it implements file creating, saving and reading functions through virtual serial ports. File saved in the SD card can b(?) directly read by PC. This scheme provides an effective way to solve the embeded system memory bottleneck problem, and achieves the goal of extending embeded system memory. |
