16 bit binary to decimal decoder
May 20, 2020
A simplified representation of a decoder:
The idea of a decoder
Some key data first:
front of the decoder
backside of the decoder
The complete thing works parallel, thus it's very fast in processing data. Maybe the whole part will get too big, but let’s wait and see.
Now the second prototype without these bypass tracks:
logic gates for the 2nd board type
And this method is called double dabble. It got invented in 1960 and can also be done by hand or without a paper only in your head. I use the hardware version and is as follows:
It is a circuit which adds 3 when the number is greater than 4. (add 3 if i >= 5)
Here you can see how it works:
logic design
The same circuit with the NAND NOR NOT standard:
better logic gate design
Schematic for this circuit:
zoom into top schematic
zoom into bottom schematic
This is the PCB for the second prototype.
The setup for testing.
Maybe you did not noticed but the INPUT is 0110 (6). Because of that the OUTPUT is 1001 (6+3=9).
test build
And the finished board. Tested, sealed and ready to use.
front view of the board
back view of the board
Unfortunately, a few mistakes have occurred:
The drill was too tiny (0,5 mm) and destroyed the copper around the pads. So I got an 0,8 mm drill now.
failed drilling