Datasheet

CD54AC161, CD74AC161
4-BIT SYNCHRONOUS BINARY COUNTERS
SCHS239C – SEPTEMBER 1998 – REVISED MARCH 2003
2
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
FUNCTION TABLE
INPUTS
OUTPUTS
FUNCTION
CLR CLK ENP ENT LOAD A,B,C,D Q
n
RCO
FUNCTION
L X X X X X L L Reset (clear)
H ↑ X X l l L L
Parallel load
H ↑ XX l h HNote 1
Parallel
load
H ↑ h h h X Count Note 1 Count
H X l X h X q
n
Note 1
Inhibit
H X X l h X q
n
L
Inhibit
H = high level, L = low level, X = don’t care, h = high level one setup time prior to the CLK
low-to-high transition, l = low level one setup time prior to the CLK low-to-high transition, q = the
state of the referenced output prior to the CLK low-to-high transition, and ↑ = CLK low-to-high
transition.
NOTE 1: The RCO output is high when ENT is high and the counter is at terminal count
(HHHH).