What is 2421 code?

[jmcoreymv]

Im working on my Digital Design HW and the problem wants me to build a circuit to convert BCD code to 2421 code. I cant figure out what 2421 code is, I cant find it in the book/index, and I cant find it on google. Does anyone know?

 

[FoBoT]

you need to work on your googling skillz

first link off google

2421 Code
This is a weighted code, its weight are 2, 4, 2 and 1. A decimal number is represented in 4-bit form and total weight of the four bits = 2 + 4 + 2 + 1 = 9. Hence the 2421 code represents decimal number 0 to 9.

 

[jmcoreymv]

Wow must of missed that. Alright cool thanks. Do you know why 2421 is useful?

 

[FoBoT]

Originally posted by: jmcoreymv
Wow must of missed that. Alright cool thanks. Do you know why 2421 is useful?

useful? you mean as opposed to other code/numbering systems?


hmm....


maybe like other 4 bit codes , the components to use them are cheaper? or cause number pads/displays are 4 bit ?


i dunno

be careful, this one is more technical, my brain almost exploded

does this mean something?

Excess-3 and BCD 2421 were devised so that bitwise complementation
will give the 9's complement (the radix 2 analog of 1's complement)
of the decimal number, making hardware implementation require more
simple circuitry.