Study Of Data Storage Based On The ARM And USB-Host In Chemical Irradiance Detecting System

The paper introduces a kind of CIDS (chemical irradiance detecting system) based on the ARM core processor and the USB-Host particularly. The CIDS completes the system data collection, the man-machine conversation, the bulk-data preservation successfully, and adds the operation systemμC/OS-Ⅱto support the project and the peripheral devices. This project's USB-Host has completed the USB core driver, the HCD (host controller driver) as well as the user program, has supported the MassStorage protocol for device class, and has established the simplified FAT16 filesystem on them, then it can fetch the file data from the U plate, and feedback the results of test directly through LCD(Liquid Crystal Display).Generally speaking, USB technology of the operation system aims at the PC (personal computer) primarily, just for the development of USB device class, so if USB device was separated from PC, then it shouldn't have no significance for its own function. This paper avoids the limitation of PC, uses the ARM chip and the USB HCD to control the USB device.The hardware design of the CIDS is constructed by the S3C44B0 chip and the SL811 controller, since their features contain low-cost, low-power, and the high speed and satisfy the feasibility analysis to the system design. In the aspect of software code, the CIDS completes transaction driver, transmission driver, device description, and device enumeration gradually. After those, the USB1.1 protocol stack is established, MassStorage protocol stack and FAT16 filesystem are added to the software structure. Then the whole system is able to complete the visit of U plate.This paper not only completes the test performance of CIDS, but also completes the depth index for CIDS. Based on the structure of original single directory, the paper changes it to the more index-nodes for different patients' data. Through the new method, the different level patients' cases are managed in the same storage and the bulk data is saved regularly and also the turbulence of test results is avoidable.μC/OS-Ⅱgives the consistent and optimized visit mode to the system tasks, but the task for U plate must obey the low speed of U plate visit, it restricts man-machine conversation and makes the system not professional. So the paper attempts to change the restriction and constructs the special methods to avoid the data turbulence of different tasks' visit. The paper also introduces the software mechanism like this: new code is inserted into operation system according to theμC/OS-Ⅱprinciple.Based on the method proposed in the paper, The USB-host system construction of CIDS has been completed successfully; it has universal significance for the embedded USB-Host system development. Finally, the paper makes the conclusion for CDIS, especially for the USB-Host system development, and also points out the prospects for the embedded USB-Host system.