Serial Extended Protocol Based On SOC IP Soft Core Design

IC is developing to ultra deep sub-micron scale, the circuit functions in one chiphave become richer and richer. System level Chip (System On Chip; SOC) designbecomes the key of the integrated circuit design. Increasingly complex design doesnot allow the engineer to design all the modules individually. Design method based onIP has become the mainstream design way.Nowadays, SPI, IIC, UART can meet serial communication needs in differentsituations well, thus becoming thier standards repectively. Enginners often integratethe IP cores of SPI, IIC, UART in one chip to support these IP at the same time. Thisway is simple but not the best choice. One enginner has successfully extendedprotocol of SPI to communicate with the UART, but there is no design method thatcan integrate three protocols above.Based on the above reasons, this article proposed a method of extended SPIcommunicating with IIC. Through the analysis, a serial protocol design method whichmerges three serival protocols together in one IP is proposed. This IP can flexiblyconfigure three protocols of SPI IIC UART, reducing the using of IP logic cells.In accordance with the method of extended serial protocol IP design which isbased on APB protocol, detailed design of IP structure is given. Based on the demandof this IP, state transfer diagram is described. Then, all the functions of IP areimplemented by Verilog HDL language. Finally, the IP has passed the simulation ofVCS and the statistics result of verify coverage has be given. The design also passedlogic synthesis, timing analysis and equivalence verification. Verification result showsthis design can meet expected results and the area is smaller than three separate IPlogic using. Extended SPI protocol can properly communicate with the IIC and UART.It illustrates the practicability and engineering value of the IP.