Design Of Ventilator Controller Based On ARM And AVR With The Architecture Of Dual CPU

With the development of computer technology, digital and analog circuit discrete control mode has been replaced by CPU control mode. In this background of ventilator industry, Beijing Kang Do company (Kang Du medical Apparatus and Instruments CO.LTD) joins with North China University of Technology in developing new products which is based on the Microprocessor. There are two characteristics on this ventilater controller: First, as a medical apparatus, it must have security with higher degree; Secondly, There should be a good Human-Machine Interface.The main contents in this paper includes:(1) Choose of control scheme. In view of these functional requirements, we design the hardware architecture of controller based on dual CPU mode: S3C44B0, which is a ARM7 processor, is used for measurement, control, key processing, display and other routine tasks; ATmegal28, which is a AVR Microcontroller, is responsible for issuing the clock pulse for whole machine.(2) Desing of hardware.Hareware circuit desing includes three parts:The first part is the core of controller-main CPU S3C44B0.The second part is expansion of main CPU,such as power circuit,reset&watchdog circuit, oscillator circuit,debug interface circuit,memory expansion circuit.The third part is the expansion of measurement,control,display and key response circuit.(3) Design of software.Software design includes two parts:software for main CPU and software for sub CPU,The idea of both parts is circulation+interrupt.All kinds of sub-functions are encapsulated for higher level software such as display module,key response module,measurement and control module.These software realizes the required functions for Ventilator Controller.The Ventilator Controller which discussed in this paper has not only higher reliability but also better human-machine interface.