Lookup table initialization
US4751446A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 6, 1985 |
| Grant date | Jun 14, 1988 |
| Priority date | — |
| Expiry date | Dec 6, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G5/06
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a display system for a data processing system color words for display at sequential pixels are obtained by addressing a lookup table memory with addresses obtained from a bit map display memory. Initialization data is stored in the display memory and, during an initialization procedure, is applied to the lookup table along the same data path used by the addresses during display. In one system a multiplexer takes the form of a shift register into which sequential pixel addresses are applied in parallel to interleaved stages. The two LUT addresses are read out sequentially by shifting the shift register. During the initialization procedure shifting is disabled and the interleaved address and data bytes are applied along separate address and data lines to the lookup table. One data path can be utilized for either eight plane or four plane display. In another system, a buffer storage is provided between the address input to the LUT memory and the data input and, during the initialization procedure, data is stored in the buffer in alternate cycles of the display memory output.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.