Design And Implementation Of Didital Circuit For Digital Temperature Sensor

The application and development trend of digital temperature sensors is describedand the significance of this topic is explained in the article. Digital circuit of thedigital temperature sensor is designed with Verilog language and using Modelsim,ISE, Design Compiler and other tools. It includes introduction of the circuit, theprinciple of operation, key points of the design, functional simulation, FPGAverification and realization of the circuit layout.The general flow of ASIC design is described, from concept of the design, code,functional simulation, FPGA verification, logical synthesis, static timing analysis,formal verification, layout, to the post-layout simulation, chip testing in this article.The design flow of the digital temperature sensor is based on the flow of ASIC design.The flow of digital design is from understanding I2C protocol, function of chip,division of the module to post-layout simulation.The digital of the digital temperature sensor is divided two modules, I2C slavemodule and compare/interrupt module according the function. I2C slave moduleincludes I2C slave interface and registers. Registers are read and wrote according I2Cinterface. The transmission of I2C have five kinds, including writing a single byteregisters, writing double byte registers, reading a single byte registers, reading doublebyte registers, reading registers without the address of the registers. The data istransmission via asynchronous clock domain about temperature register in thismodule. It is special treated to ensure correct transmission. Compare/interrupt modulehas two modes of operation, comparator mode and interrupt mode. It is selecteddifferent operating modes according to the actual needs. The selection of outputpolarity and fault queue are increase the availability and reliability of the chip. Toensure proper operation of compared the temperature, the asynchronous clock isspecial treated. After Verilog implementation of the digital circuits, it is verified withISE and FPGA.The digital circuit of digital temperature sensor layout is based on MXIC0.35μmCMOS technology library. The digital circuit is constrained base on the I2C timing,rules and process design requirements in logical synthesis. The gate-level netlist aftersynthesis and RTL-level netlist before synthesis are formal verified to ensure theconsistency of the two netlist. It is placed and routed after verification in ICC. The whole process is accompanied by static timing analysis to ensure timing convergence.It is formal verified after layout. The final netlist from ICC is verified with timing.