How works a Binary up/down counter 4-bit presettable(IC SN 74 LS 191)

Could someone try to explain me how it works. and what al dips are for,
the data sheets that i already used are,
SN74LS191 pdf, SN74LS191 description, SN74LS191 datasheets, SN74LS191 view ::: ALLDATASHEET :::
https://www.electro-tech-online.com/custompdfs/2010/02/169676-da-01-en-74LS190_191.pdf

But i can't trigger it out

Great thanks,
My

its a programmable binary coded decimal up down counter. it is used in clocks . but you can use it for a varierty of other things. the basic ifunction is its four flipflops shifting 1's and zeros aka counting. you connect ce to ground enanling the clock. connect cp to a clock puls or oscilator dealy q0 -q3 are your outputs . when pl goes low it loads the bcd number you put into p0 -p3. if u/d is high it counts up if its low it counds down. rc and tc have to do with using the chip as a ripple counter. look up ripple counters i for get what the importance of that is exactly. most of what i remember from school revolves around the 74293 which is what i built digital clocks with. but i useal all of these chips at one point or another.

for some reason i remember disliking this chip. i think in order to use it normally you have to have make it preset zeros or some dumb thing i forget