The Programming Circuit And Programming System Design Of The Anti Fuse OTP Memory

Anti-fuse OTP ROM(PROM)is one kind of one-time programmable read only memory,it uses the anti-fuse structure as its basic memory cell.While the anti-fuse layer is breakdown,its resistance will change a lot,and the data is saved.The way PROM saves data determines it’s more stable and reliable compared with flash memory which saves data by the charge change,so that it can be used in aerospace industry where the radiation is strong.In this article,first of all to introduce is the design and simulation of programming circuit for 256 KBit PROM which is based on 0.5μm process from CSMC,including the design and simulation of the overall programming circuit,the programming control module,the oscillation circuit module and the charge pump module.The second to introduce is the design and simulation of the programming circuit layout,including the design of the layout,the LVS and the DRC of the layout,the extraction of parasitic parameters in layout and simulation.The simulation results show that the programming circuit is reliable.While data ‘1’ is saved in PROM,a high voltage is needed to breakdown the anti-fuse,it’s necessary to design a professional programming system,providing programming service and data checking service for the PROM.Before using the PROM,data must be saved in it,then it’s necessary to verify if the data being programmed in the PROM is the same with the data which is needed to be saved,the difference means the programming is failed.The programming system consists two parts: the program and the hardware circuit.First of all to introduce is the overall design of the programming system,including the hardware circuit plan design and the software plan design.The second to introduce is the hardware circuit design,including the control circuit and its peripheral circuit,the power supply circuit,the transfer board circuit.The control circuit contains a STM32 micro controller unit as it’s core,which is also the core of the programming circuit.The peripheral circuit includes the programming voltage generating circuit,the communication interface circuit and the resistance detection circuit.The power supply circuit is responsible for providing operating voltage for the whole programming circuit and PROM.The transfer board circuit provides a interface between the programming system and the PROM.The last to introduce is the programming design for the programming system.The programming design consists two parts: the host computer software design and the STM32 control program design.The host computer software is designed by C#,which can exchange data and instructions with STM32 through the serial port.While the lower position machine receiving data and instructions from the host computer,the control program will drive the peripheral circuit work,completing the data programming and data checking.The programming system finally will be able to program data into PROM and read data from the PROM.