PRE and CLR

[Spectacular Butter]

Hi i am simulating a D Flip Flop with CLR and PRE

Both PRE and CLR are active low.

Why is it that when i put PRE and CLR low simultaneously, both my Q and /Q will be a 1. Is there an explanation why this happens?

I am writing a report on the simulations i did but i can't seem to find a book that explains why this happens.

 

[2PAC Mafia]

Hello,

may be on the datasheet of the flip flop there is the internal scheme and then you can understand the way they design it...