Researching And Realization Of Mathematical Operation System Of Universal Calculator Chip Based On 4bit MCU

A CMOS LSI calculator chip with 4bit MCU core can finish various functions, display driver, keyboard scan and so on. The article researched the technology about MCU, and various arithmetic. By the demand of calculator's function, it presented the hardware architecture and arithmetic model of calculator's chip, and finished the core of calculator's chip-MCU design.Design adopted as "top-down" approach, according to normal idea of computer system's design, it is divided four steps: hardware architecture's design, instruction system's design, analysis of instruction, micro-instruction format's design and mircoprogrammed.The article detailed analyzed the data presentation in calculator chip and four arithmetic. At multiplication, the multiplicative arithmetic of 1 bit BCD was improved and presented new arithmetic. At division, it presented the resolvent when divisor being zero. Square arithmetic adopted as Newton-raphson arithmetic. The approach of getting initial value was improved, and it presented new approach of divided segment. Based on arithmetic model, analysis of instruction adopted as state diagram, and showed execution of various instruction. Calculator chip adopted as data path of single bus, and ALU of 4bit was the base of operation, inner RCOSC produced stable clock source, SRAM adopted as memory, and microcontroller adopted as ROM architecture.The new calculator chip of the article design was not only a independently product, but also was developed new products, such as PDA, etc.