4029 CMOS可预制加、减(十、二进制)计数器

The CD4029BC is a presettable up/down counter which
counts in either binary or decade mode depending on the
voltage level applied at binary/decade input. When binary/
decade is at logical “1”, the counter counts in binary, otherwise
it counts in decade. Similarly, the counter counts up
when 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 asynchronously
with the clock. The counter is advanced one count
at the positive-going edge of the clock if the carry in and
preset enable inputs are at logical “0”. Advancement is
inhibited when either or both of these two inputs is at logical
“1”. The carry out signal is normally at logical “1” state
and goes to logical “0” state when the counter reaches its
maximum count in the “up” mode or the minimum count in
the “down” mode provided the carry input is at logical “0”
state.
All inputs are protected against static discharge by diode
clamps to both VDD and VSS.