1. Without regular time relationship;unexpected or unpredictable with respect to the execution of a program's instructions.
沒有規則的時間關系,對程序指令的執行是無法預料或不可預測的。

2. Having a variable time interval between successive bits, characters or events. In data transmission, this is limited to a variable time interval between characters, and is often known as start-stop transmission.
在時間上相鄰的兩位、兩個字符或兩個事件間的時間間隔是不規則的。

在數據轉輸中,僅 指相鄰字符間的時間間隔不規則。

這種傳輸方式通常稱起止式傳輸。

參閱synchronous。