| 摘要 |
<p>A digital timer apparatus (10) incorporates a free running counter (12), an interval timer (18), a capture register (14), a pulse accumulator (20) and holding logic (16, 22). A rising or falling edge of an external signal causes the current contents of the free running counter (12) to be loaded into the capture register (14) and causes the pulse accumulator (20) to be incremented. The output of the interval timer (18) can cause the contents of the pulse accumulator (20) and capture register (14) to be stored into the holding logic (16, 22). The timer apparatus (10) is particularly well suited to performing tasks related to the determination of the speed of rotation of a rotating member and may be used, for instance, in detecting wheel rotational speeds in an anti-lock brake system or detecting shaft rotation speeds in an automatic transmission. <IMAGE></p> |
