Based on the ARM architecture status monitoring and design (1)

1 Introduction

As China's rapid economic development, urbanization is increasing acceleration, people constantly accelerating the pace of life, more and more people begin to feel the deterioration of health, many people never know until disease outbreak.

It is reported that the vast majority of people in China are in the Asia-Pacific health status. With modern electronic technology development, 16/32-bit CPU, traditional physiological signal monitors CPU system is gradually by the 8-bit CPU to a higher number of processors. With the monitor function of powerful data processing speed of the increasingly high demands, enabling the development of an 8-bit CPU was restricted, 16/32 bit CPU can be much higher than the 8-bit CPU clock frequency, data throughput, processors once prices are falling, 16/32 bit CPU began to be widely used in physiological signal monitor.

The monitoring system adopts ARM7 series chip embedded microprocessors in LPC2292, mainly used for measuring the body's physiological parameters, such as: ECG, blood pressure, oxygen saturation, temperature, etc.

Because the system requires the collecting and processing large amounts of data information and CPU used single-task software to process these data information is very difficult, even impossible. Therefore the design selection can handle multiple tasks simultaneously μ C/O S-Ⅱ operating system. It provides a secure and reliable operating system platform, reducing the development cycle.

2 system hardware design

ARM 7 series chip LPC2292 minimum system as shown in Figure 1:

System's overall structure diagram as shown in Figure 2:

Figure 2 shows the entire system to ARM 7 LPC2292 series chip at the core, extended its perimeter fringe circuit, enabling the human physiological parameters: ECG, blood pressure, oxygen saturation, temperature of the security check.

System through the ECG module, blood pressure, oxygen saturation, temperature module acquisition the body's physiological parameters, these signal conditioning circuits for filter and amplifier, LPC2292 comes with A/D converter will transfer over from analog signals into digital signals, the last of the human body through the LCD displays the parameter index.

2.1 ARM system module

ARM system is the system's control center, the main completed operations, control, management, and so on, is the core module of the system.

The system uses the ARM 7 LPC2292 series chip, he is based on a support real-time simulation and keep track of 16/32-bit CPU with 256 kb of embedded FLASH memory and high speed. 128-bit wide memory interface and unique acceleration enables 2-digit code to maximum clock rate. On the code size is strictly controlled by the application can use the 16-bit Thumb mode will reduce the code size is more than 30 per cent, while the performance loss is small. Because of the 144 feet LPC2292 encapsulation, extremely low power consumption, more 32-bit timer, 8-channel 10-bit ADC, 2-channel PWM channels and up to nine external interrupt make them particularly suitable for medical systems, automotive, industrial control and fault-tolerant maintenance bus.

2.2 LCD display module

LCD display module mainly completed data display and output data and display data synchronization capabilities.

Because there is no LCD controller LPC2292 function modules, if you choose LCD internal no LCD controller, then, to make the CPU can be controlled on the LCD, you must design a LCD control circuit. Therefore the system selection comes with controller HLM6323 LCD. He is a 5-inch pseudo color LCD, 320 × 240 pixels, each dot matrix requires a three-colour RGB data, each color requires a 1 byte of data representation. While the design requirements need continuous watch the map image, based on standard 25 frames per second required image, then you need at least per second data transfer to 25 × 8 × 320 × 240 = 15 360 000-bit data, optional serial transmission, you need 4.6 Mb/s serial transmission speeds, but unfortunately, there is no one serial standard transmission is greater than the speed, therefore, will need to choose a parallel data transfer.

2.3 alarm module

When measured in physiological parameters, such as ECG, blood pressure, oxygen saturation, temperature exceeds a preset normal value, the resulting alarm to remind patients quickly for treatment or health care professionals need for emergency measures.

2.4 FLASH data memory and USB interface

In order to ensure that real-time data save, and extract to design this module.

The system selects NAND08GW3D2 series memory chip. Due to the different storage density device PIN, so the system can not be altered in the circuit of upgraded to high-capacity storage devices. Via the USB device interface chip ISP1161A1 extended out a USB device interface. Through the USB interface, you can implement the monitoring system records the data on a PC, the PC or you can download a program through the interface to LPC2292 processor memory.

2.5 system power supply

Power system design is a key component in the design of the entire system, a stable, have a certain power of power supply and reasonable power management is essential.

This system has the following power: CPU core digital and analog power supply voltage + 1.8 V, CPU i/o port digital and analog power supply voltage + 3.3 V, bus isolated power supply, LCD driver power supply, inverter power supply for backlight LCD, otherPeripheral power supply voltage + 5 V power supply, etc.

3 software design

This system of software design including ARM of application development and μ C/O S-Ⅱ OS porting 2 basic parts.

The main ARM of applications include LCD display program, FLASH save program, USB communication procedures, the keyboard, scanner, A/D and alarm program. C/O μ S-Ⅱ OS is coordinating the tasks of the program LPC2292 management and scheduling. The entire system software flowchart shown in Figure 3.