Editing K-map (section)

=== How does this help me in any way? ===
'''BLOCKS!'''

The answer is blocks.

Let me explain...

Humans are very good at visual pattern recognition (if the layout favors it). By using the ''only-1-bit-change'' trick, we can now combine bits in blocks of size 1,2,4 and 8. When forming blocks, we only focus on the {{On}} bits! Leaving the {{Off}} bits alone.

Lets say there are the following 2 green output bits that we are interested in:

[[File:KMap_Example1.png]]

Question is: How can we describe these two bits using the bits from the columns and rows?

[[File:KMap_Example2.png]]
[[File:KMap_Example3.png]]

'''Row:'''<br>
The bits that we are interested in, are in the row where:

{| class="truthtable" style="border: 2px solid darkgray; padding: 2px"
| [[File:D_boxed.png]] || [[File:C_boxed.png]]
|-
| [[File:Off.png|24px]] || [[File:On.png|frameless|24px]]
|}

'''Column:'''<br>
The bits that we are interested in, are in the columns where:

{| class="truthtable" style="border: 2px solid darkgray; padding: 2px"
| [[File:A_boxed.png]]
|-
| [[File:On.png|24px]]
|}

We don't need [[File:B_boxed.png]] to describe the two columns, because [[File:A_boxed.png]] = {{On}} already covers both columns.

By putting those together, we can describe the {{On}} bits as '''2-bit block'''. The bigger the block, the less inputs we need to describe it! So we want to make the blocks as big as possible. To describe a 2-bit block, we need 3 inputs - the 4th does not matter (also a feature of our ''1-bit-change-only trick'').

[[File:KMap_Example4.png]]

The block is described by this combined input conditions:

{| class="truthtable" style="border: 2px solid darkgray; padding: 2px"
| [[File:D_boxed.png]] || [[File:C_boxed.png]] || [[File:B_boxed.png]] || [[File:A_boxed.png]]
|-
| [[File:Off.png|24px]] || [[File:On.png|24px]] || [[File:Cross_gray.png|24px]] || [[File:On.png|24px]]
|}

So now we can '''AND''' everything together and the block is done.

[[File:KMap_circuit_block.png]]