资 源 简 介
The CD4029BC is a presettable up/down counter whichcounts in either binary or decade mode depending on thevoltage level applied at binary/decade input. When binary/decade is at logical “1”, the counter counts in binary, otherwiseit counts in decade. Similarly, the counter counts upwhen the up/down input is at logical “1” and vice versa.A logical “1” preset enable signal allows information at the“jam” inputs to preset the counter to any state asynchronouslywith the clock. The counter is advanced one countat the positive-going edge of the clock if the carry in andpreset enable inputs are at logical “0”. Advancement isinhibited when either or both of these two inputs is at logical“1”. The carry out signal is normally at logical “1” stateand goes to logical “0” state when the counter reaches itsmaximum count in the “up” mode or the minimum count inthe “down” mode provided the carry input is at logical “0”state.All inputs are protected against static discharge by diodeclamps to both VDD and VSS.
