【正文】 sent work, the sensor which is kept very near proximity to the IC will sense the temperature and the speed of the fa n arranged near to the IC is controlled based on the PWM signal generated by the ARM processor. A buzzer is also provided with the hardware, to indicate either the failure of the fan or overheating of the IC. The entire process is achieved by developing a suitable embedded C program. Keywords: Temperature sensor, ARM processor, VLSI chips, Brushless DC motor 7 With the phenomenal developments in VLSI technology, the ambitious IC designers are trying to put more transistors in to smaller packages. So, the ICs run at higher speeds and produce large amount of heat which creates the problem of thermal management. For example, nowadays the CPU chips are being smaller and smaller with almost no room for the heat to escape. The total power dissipation levels now reside on the order of 100 W with a peak power density of 400500 W/Cm2, and are still steadily climbing. As the chip temperature increases its performance is very much degraded by parameters shift, decrease in operating frequencies and outof specification of timings. So the high speed chips must be cooled to maintain good performance for the longest possible operating time and over the widest possible range of environmental conditions. The maximum allowable temperature for a high speed chip to meet its parametric specifications depends on the process and how the chip is designed. Among the various cooling techniques, heat sinks, heat pipes, fans and clock throttling are usually employed. Among these techniques, fans can dramatically reduce the temperature of a high speed chip,but they also generate a great deal of acoustic noise. This noise can be reduced significantly by varying ,the fans speed based on temperature . the fan can turn slowly when the temperature is low and canspeed up as the temperature other prominent method is clock throttling . reducing the clock speed to reduce power dissipation. But it also reduces the system performance and the systems functionality is , the objective of the present work is, to design a hardware system consisting of a brushless DC motor fan whose speed is controlled based on the temperature of the chip, sensed by the sensor LM35 series are precision integratedcircuit temperature sensors, whose output voltage is linearly proportional to the Celsius (Centigrade) temperature. The LM35 thus has an advantage over linear temperature sensors calibrated in Kelvin, as the user is not required to subtract a large constant voltage from its output to obtain convenient Centigrade scaling. The LM35 does not require anyexternal calibration or trimming to provide typical accuracies of 177。因此，目前的工作可以使用上述 技術 進一步提高 。 第一個 IC 可以檢測 到遠程溫度 然后通過溫度來控制風扇風速 。 另一個重要 方面是各種傳感器的遠程溫度高達 五個傳 感渠道，可以 將 檢測 到的高速芯片的溫度數(shù)據(jù)傳送到微控制器。因此，為了避免這些影響 ， 風扇的驅動器信號必須限制在一個可接受 范圍內 。 在一些系統(tǒng)中 ， 限制風扇的速度變化率也是重要的。這是通過 調整 一個低頻 約 50 Hz 的 PWM 信號 的 占空比變化來調整風扇的速度。 使用遠程 二極管溫度傳感器連接到這個熱二極管，得出的結果 可以 與 直接測量 VLSI 芯片 一樣精確 。以這種方式 檢測 高速芯片 的溫度與實際溫度較為接近 ，但 也有可能 測量溫度 比 管芯溫度上升 時溫度要低 。這些結果 在 LCD 液晶顯示面板 上可以看見 。為了驗證設計的有效性，溫度傳感器 被放在一個比室內溫度高的 烤箱 內 。 32 位定時器， 10 位 DAC，一個 PWM 單元， 一個 CAN 控制裝置，以及多達 70 個的 GPIO 線路 和 12 個外部中斷引腳使這個 單片機 特別適合 應用在 工業(yè)控制和醫(yī)療系統(tǒng)等。 對于重要代碼應用，其他 16 位 代碼在 Thumb 模式 性能損失 可減少超過 30％ 。在系統(tǒng)編程 這一環(huán)境下我們可以 采用引導加載器軟件和 使用 一個串行端口 進行編程 或重新編程 閃存 記憶體 中的程序 。 LCD 圖形液晶顯示器（ 128x64 像素）的接口 與 ARM LPC 2378 處理器相連，