The Function Design Of Chinese-braille Translation SoC Based On Cortex-M3

Braille is a special system of writing designed for the blind that conveys information through touch,and is crucial in areas such as education,information access,and social inclusion for the visually impaired.However,blind individuals face limitations in accessing learning and life conveniences in the age of information due to the inherent limitations of Braille paper books,including limited information capacity and high cost.To promote the development of Braille information accessibility and improve the translation speed of Chinese to Braille under low computational power,this thesis presents a Chinese-Braille translation SoC system based on Cortex-M3 that can perform functions such as Chinese input and Braille point sequence output and display.This thesis proposes a hardware-based Chinese-Braille translation method that uses a reverse maximum matching algorithm and a word segmentation lexicon to achieve Chinese word segmentation,dividing the text into meaningful vocabulary.The segmentation results are then processed using a Chinese-Braille comparison lexicon and binary search algorithm to complete the entire Chinese-Braille conversion process.To improve the efficiency and accuracy of Chinese-Braille translation,a participle thesaurus and Chinese-Braille comparison lexicons are produced that are classified and arranged according to the word length and coding order respectively.The entries in the ChineseBraille comparison lexicon consist of Chinese Unicode data,Braille digits and Braille dot sequence,and are divided into four comparison databases according to the differences of Braille schemes: general braille,full-tonal current braille,non-tonal current braille and double spelling braille to basically meet the reading needs of visually impaired people in China for different Braille conversion schemes.According to the overall functional analysis of the system and the co-design process of software and hardware,this thesis constructs the top-level structure of a customized Chinese-Braille translation SoC.The structure uses a lower-grade Cortex-M3 processor core to enable control logic and data interaction with peripheral devices via AHB and APB buses.At the same time,the working principles and usage scenarios of these two buses are analyzed,and the AHB bus mounts devices with high frequency of use and large computational loads,including ITCM,DTCM,and the Chinese-Braille translation module;while the APB bus mounts low-power and low-bandwidth peripherals,including UART,SPI,GPIO,etc.In addition,a bridge is used to connect AHB and APB.This architecture design can effectively improve the efficiency and performance of the system.In the design,a modular design approach is adopted and described using Verilog HDL language to implement peripheral hardware devices in the system.For the ChineseBraille translation method,a dedicated Chinese-Braille translation module is constructed,which realizes functions such as Chinese word segmentation,conversion of single and multiple characters into Braille,and Braille concatenation,ultimately achieving the entire process of Chinese-Braille translation.The word segmentation and Braille comparison lexicons are stored in an external Flash memory,and data read and write to any address and word length is achieved through the Flash read/write module.To assist the processor and Chinese-Braille translation module,a serial transmission module is designed for receiving text data outputted by the host computer and transmitting Braille code sequences,while also responsible for controlling the Braille display showing Braille characters.Additionally,an LCD display driving module is designed to simultaneously display text information and Braille code sequences,facilitating comparison and analysis of the translation results by designers.After the design was completed,a software driver program was developed based on the entire hardware system design,using Modelsim for functional simulation and timing analysis to verify the logical design.Afterwards,the Vivado integrated development tool and FPGA hardware platform were used for prototype verification to analyze its resource utilization,power consumption,and synthesis timing,ensuring design accuracy.After rigorous testing and verification,the Chinese-braille translation chip designed in this thesis has achieved the complete Chinese-braille translation process,effectively distinguishing polyphonic words,and has a high accuracy of about 98.84% and a fast conversion speed of 8000 bytes/s.