Posts Tagged ‘Cool Circuits’


Polymorphic Circuits

July 14, 2008

Here is a neat and not so new idea that I came across last year – “Polymorphic Circuits”. The basic concept is logic gates which under specific operating conditions behave in a certain way while under different operating conditions behave in another way. For example a circuit when operated with a 2 volt supply might act as an OR gate but when supplied with 1 volt will become an AND gate, or another example might be a circuit which in room temperature behaves as an XOR gate while at 120 degrees, the very same circuit operates as a NAND gate.

This concept just screams for new application (I guess mainly in security) but I was not able to think of something specific so far. Feel free to shoot ideas around in the comments section of this post.

In the meantime more details can be found on this paper (just skip to the images at the end of the paper to get the idea), or this paper.


Edge Triggered SR Latch

June 18, 2008

I never really used an edge triggered SR latch in any of my circuits before, but I dug this from my bag of circuit goodies and it is just too nice not to share (does it show that I am designing circuits for too long?)

The basic idea is to use two regular run-of-the-mill flip flops and combine them to a single “SR latch like” construction which is edge triggered.
The circuit is displayed below, and I just can’t help it – admiring a circuit with some sort of cross coupling…

And a corresponding timing diagram: