I did a search on "TTL Compatibility." I am redesigning an old circuit because the part it was built around is no longer available. The data sheet for the new part I am using, a High Speed CMOS SRAM, states that all inputs are TTL Compatible, which implies to me that other items on the bus can use 5V TTL logic. But then the data sheet states that Vih Max (hi input voltage) is Vdd + 0.3V. My concern is that TTL Compatible may not mean what I take it to mean, so I came here to see if I could learn anything.

I didn't find anything from any of the returned threads.

One of the returned posts was
http://www.8052.com/forum/read.phtml?id=37908

The subject for that post is "other compatibility problem"

Here is the text of that post.


Can you tell yet, why that post was returned? Obviously the word "compatibility" is right there in the subject. But it never mentions TTL. Look again, and see why it returned.



Did you spot it this time?

Now, I am not suggesting that Craig take time out of his life to make this search function any better. But I think there might be a good argument for us to be just a bit more patient before handing out any of those "Didn't Search First" scores.

Just a thought.

Joe

P.S. I was right. When ISSI writes "TTL Compatible," they are not talking about the I/O logic levels. Better learned now than after parts are bought and boards are built.