Datasheet

3
MODE SELECT - FUNCTION TABLE FOR ’HC161 AND ’HCT161
OPERATING MODE
INPUTS OUTPUTS
MR CP PE TE SPE P
n
Q
n
TC
Reset (Clear) L XXXXXLL
Parallel Load H ↑ XX l l LL
H ↑ X X l h H (Note 1)
Count H ↑ h h h (Note 3) X Count (Note 1)
Inhibit H X I (Note 2) X h (Note 3) X q
n
(Note 1)
H X X I (Note 2) h (Note 3) X q
n
L
MODE SELECT - FUNCTION TABLE FOR ’HC163 AND ’HCT163
OPERATING MODE
INPUTS OUTPUTS
MR CP PE TE SPE P
n
Q
n
TC
Reset (Clear) l ↑ XXXXLL
Parallel Load h (Note 3) ↑ XX l l LL
h (Note 3) ↑ X X l h H (Note 1)
Count h (Note 3) ↑ h h h (Note 3) X Count (Note 1)
Inhibit h (Note 3) X I (Note 2) X h (Note 3) X q
n
(Note 1)
h (Note 3) X X I (Note 2) h (Note 3) X q
n
L
H = High voltage level steady state; L = Low voltage level steady state; h = High voltage level one setup time prior to the Low-to-High clock
transition; l = Low voltage level one setup time prior to the Low-to-High clock transition; X = Don’t Care; q = Lower case letters indicate the
state of the referenced output prior to the Low-to-High clock transition; ↑ = Low-to-High clock transition.
NOTES:
1. The TC output is High when TE is High and the counter is at Terminal Count (HHHH for HC/HCT161 and ’HC/HCT163).
2. The High-to-Low transition of PE or TE on the ’HC/HCT161 and the ’HC/HCT163 should only occur while CP is HIGH for conventional
operation.
3. The Low-to-High transition of SPE on the ’HC/HCT161 and SPE or MR on the ’HC/HCT163 should only occur while CP is HIGH for
conventional operation.
CD54/74HC161, CD54/74HCT161, CD54/74HC163, CD54/74HCT163