利用傳感器集線器提高性能和功耗

　　傳感器已成為許多系統(tǒng)中的常規(guī)功能。它們與許多其他外圍設備共存，可以添加到系統(tǒng)所做的工作中的環(huán)境輸入范圍。然而，在一些系統(tǒng)中，傳感器的數(shù)量有可能壓倒其他更傳統(tǒng)的外設，并且可能比其他外圍設備更影響性能。

　　沒有什么比智能手機更大的問題了。從一個或兩個具有專用功能的傳感器，移動平臺戲劇性地增加了傳感器的數(shù)量，并向有夢想的開發(fā)人員打開了傳感器數(shù)據(jù)。建筑師可能從來沒有設想這些應用程序，當他們納入傳感器。

　　其結果是，當觸摸屏直接連接到應用處理器（AP）時，傳感器（包括屏幕的觸摸傳感器）成為了一個負擔。環(huán)境光傳感器，接近，加速，旋轉，甚至磁場、壓力、濕度、輻射、化學傳感和在不久的將來，它可以將傳感器的管理從AP的意義。

　　If the AP needed every piece of sensor data， there might be no choice but to flood the AP with that data. However， sensors， if they are doing their job， simply report what they see. At their most basic， they do not ascribe meaning to that data – that is what the processor does. Sensors have become more intelligent over the last few years， but there is still a limited range of decisions that the sensor can make. After that， some processor must decide what， if anything， to do with the data.

　　While the AP is ultimately likely to use relevant data， it can be a fair bit of work just to keep track of the data and decide what is relevant. Just as dedicated circuitry handles the radio， video， graphics， and other intensive functions， so a sensor hub can free up processor bandwidth by shielding the AP from sensor events that are likely to be ignored. By allowing the AP to sleep， a sensor hub can also lengthen battery life， even while sensors may still be active.