How to use 74HC221 for output variable pulse width on negative edge.
I tried connect B and MR pins to HIGH and A pin to input as tells in datasheet. But it give huge pulse like 1 second.
Probably I must use RX and CX pins but don't know how to use and datasheet doesn't tell.
The pulse that i want, must be between 0-10 ms.
I add R4, R5 and C3 change the values of R4 and C3 multiple times but it didn't change the output.
Then realized this:
"Pin 'CX' is not modelled.
Pin 'RX/CX' is not modelled."
in simulation log. Could this be the problem?