NAND and NOR Gates
Contents
NAND and NOR gates are preferred over AND/OR/NOT gates as they require less transistors to implement
| Gate | # Transistors |
|---|---|
| NOR | 4 |
| NAND | 4 |
| NOT | 2 |
| AND | 6 (NAND + NOT) |
| OR | 6 (NOR + NOT) |
NAND conversion (SOP network)
| Step 1 | Step 2 | Step 3 |
|---|---|---|
 |  |  |
- Replace AND & OR gates with equivalent NAND gates
- Ensure the logical value of no wire is changed due to step
- Insert additional bubbles into wires where only one bubble was added during step 1.
- Add bubbles to the outputs of every AND gate
- Add bubbles to the inputs of every OR gate
- Replace OR gates with bubbled inputs to NAND
NOR conversion (POS network)
| Step 1 | Step 2 | Step 3 |
|---|---|---|
 |  |  |
- Replace AND & OR gates with equivalent NOR gates
- Ensure the logical value of no wire is changed due to step
- Insert additional bubbles into wires where only one bubble was added during step 1.
- Add bubbles to the outputs of every OR gate
- Add bubbles to the inputs of every AND gate
- Equalise bubbles
- Replace AND gates with bubbled inputs to NOR
Example 2.3
Example 2.3
