Implication gate?

[renzen]

Hi,

I need implication gate for compare 2 square wave max 1Mhz.
1 1 -> 1
1 0 -> 0
0 1 -> 1
0 0 -> 1
The only way that I know is using micrcontroller.
1. Does 8Mhz microcontroller is enough for 1Mhz square wave input?
2. Is it possible without using microcontroller to get implication gate? If yes, how?

Thanks

 

[Les Jones]

If you invert the right hand column of the input and feed it into one input of a NAND gate and feed the left hand column into the other input of the NAND gate it should achive what you want from your truth table. You can use one of the other NAND gates in the cip as an inverter by connecting the two inputs together. (Or use one inpyt and tie the other input high.)

Les.

 

[ronsimpson]

There is a IC called 74ls00. It has 4 NAND gates inside. (it is fast)
The bottom 1/2 of the picture should do what you want.
The top 1/2 will also (probably) work but it does not exactly match what you asked for.
Top bottom
11>0 11>1
10>1 10>0
01>1 01>1
00>1 00>1