| Diabetes mellitus is a chronic disease that seriously damages human health.Portable glucose meter can be used to monitor blood glucose to diagnose and treat diabetes mellitus.In the portable glucose meter chip,Flash controller provides the timing control circuit for CPU to access flash memory.According to the characteristics of flash memory,this paper designs and implements a flash controller based on SoC system of blood glucose detection.Compared with the traditional flash controller,the flash controller supports different program download modes,including ICP download mode,SWD download mode and SSP self programming mode,In SWD mode and SSP mode,flash can be erased,written and read by controlling the timing of AHB and APB interface signals.In ICP download mode,flash can be accessed by controlling the timing of clock circuit and data circuit,which simplifies the data path;The prefetching function is also added in the read operation.The bit width expansion technology is adopted,and the flash IP with 64 bit width is selected.Two 32-bit instructions can be obtained each time,It can improve the reading speed in the scene of program sequential finger fetching;After the chip is powered on,the power supply,clock and ADC reference voltage are adjusted.When power on,read the relevant data stored in flash and output it to the system control module for adjustment;In addition to the traditional erase and write lock operation,also added a new read and write protection mechanism,each sector for write-and-write protection,the entire Flash storage area for read protection,by setting the corresponding keywords to judge whether the read and write protection is effective,to prevent the user program from being illegally tampered and stolen during power on,reset and system operation.This paper improves the efficiency of verification through three stages of verification.In module level verification stage,the traditional verification methodology has great limitations in randomness and reusability,which can not meet the requirements of this paper.Therefore,this paper develops a verification platform based on UVM universal verification methodology,designs and implements the reference model,scoreboard,driver and other components of flash controller,The random incentive and automatic comparison strategy are flexibly used to ensure the completeness of verification.In system level verification stage,the verification platform based on C language and System Verilog language is built.The test cases,common library functions and startup functions of flash controller are designed and implemented to ensure the correctness of system level connection and interaction with front and back levels.Finally,the prototype verification based on FPGA platform is implemented before the chip is streamed,and the verification environment of software and hardware cooperation is developed to simulate the actual operation environment of the chip to verify the flash controller,which provides a platform for the application software development of the chip and improves the progress of software development.The module level code coverage rate of flash controller designed in this paper is more than 95%,and the function coverage rate is 100%,which reaches the verification index;The flip coverage of system level verification reaches 100%,which indicates the correctness of flash controller interconnection at system level;In the FPGA stage,the netlist with delay information after generic cabling is downloaded to the FPGA board for verification.The verification results show that the function and performance of FLASH controller meet the requirements of the system. |
