Dual port memory, such as used in color lookup tables for video systems
US5325338A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 4, 1991 |
| Grant date | Jun 28, 1994 |
| Priority date | — |
| Expiry date | Sep 4, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S257/903
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An integrated circuit memory for a color lookup table for a display system. The memory has a video port and path for reading data identifying colors for pixels at >100 or even >200 MegaHertz, and a CPU port and path for reading and writing data identifying colors at locations in the memory. Each memory cell includes a flip-flop with true and complement terminals. The CPU port includes two pass transistors, each having a first channel terminal coupled to the true or complement terminal, a second channel terminal coupled to a bidirectional bit line of the CPU path, and a gate coupled to a word line of the CPU path. The video port includes an isolated sensing terminal and two transistors. A first transistor has a first channel terminal coupled to the isolated sensing terminal, a second channel terminal coupled to a reference, and a gate coupled to the true or complement terminal. A second transistor has a first channel terminal coupled to the isolated sensing terminal, a second channel terminal coupled to a bit line of the video path, and a gate coupled to a word line of the video path.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.