[email protected] wrote:

> There chips with the mixture of Active HIGH and Active LOW signals. Is
> there any pros and cons of each levels? OR it simply choice of
> designers / manufacturers?

I believe for TTL there is some advantage to active low for
enables and such. TTL has much better current sinks than
current sources. I don't believe the advantage is as big,
if any, for CMOS but may have been kept for backward
compatibility reasons.

-- glen