| ??? 09/18/08 18:29 Read: times |
#158370 - Negative In - Positive Out Responding to: ???'s previous message |
Negative In / Positive Out, and vice-versa, does exist.
For example, I have seen NAND gates drawn as OR gates, with inversion bubbles on the input. That was done to improve clarity when using NAND - NAND to implement an AND-OR sequence. If I may interject a historical note, back in the 70s when MOS was new, all devices were PMOS. PMOS requires a positive ground, and is turned "ON" by a negative voltage. Our chips were frequently done entirely in "negative" logic. One had to be quite careful when talking to outside customers who used TTL. We also reduced the power consumption by removing the supplies from most of our circuitry. The term "4-phase, dynamic, negative logic" use to strike fear into men's hearts. Now, no one knows what it means. Times have changed. |
| Topic | Author | Date |
| negartive and positive logic ... | 01/01/70 00:00 | |
| So what?? | 01/01/70 00:00 | |
| Language??? | 01/01/70 00:00 | |
| deMorgan ... | 01/01/70 00:00 | |
| deMorgan states pos AND = neg OR | 01/01/70 00:00 | |
| Is there a contradiction here? | 01/01/70 00:00 | |
| NO!, it is a negative NOR | 01/01/70 00:00 | |
| I don't follow ... | 01/01/70 00:00 | |
| negative logic / means TRUE | 01/01/70 00:00 | |
| / means NOT | 01/01/70 00:00 | |
| Negative input NOR = Negative OR | 01/01/70 00:00 | |
| I have never heard of | 01/01/70 00:00 | |
| NAND and NOR fuzzy? | 01/01/70 00:00 | |
| nope | 01/01/70 00:00 | |
| I beg to differ | 01/01/70 00:00 | |
| Negative In - Positive Out | 01/01/70 00:00 | |
| "drawn as" | 01/01/70 00:00 | |
| It's semantics ... | 01/01/70 00:00 | |
| Assertion and Negation | 01/01/70 00:00 | |
| things have changed ... | 01/01/70 00:00 | |
| Something to live with | 01/01/70 00:00 | |
OT: Freescale | 01/01/70 00:00 |