Process for sequentially reading a page from an image memory in either of two directions
US5561777A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 30, 1993 |
| Grant date | Oct 1, 1996 |
| Priority date | — |
| Expiry date | Aug 30, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C8/12
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A process of loading an image in the form of a bit map into a memory which can transfer data words in burst mode in either row or column direction. First, the memory is divided into two sections with odd words stored in one section, even in the other, which allows ping pong buffers to be reading one word from memory while the next is being accessed. Also, the page height is set to be an odd number of words. Therefore, when the entire page is read in or out, successive words in either the row or column direction will always be alternately odd and even. If a partial image is read into the memory, this odd and even relationship will also hold. If an image with an even number of rows is read in, in order to preserve the sequential odd-even sequence, in every other column of the original data successive words are swapped so that the word order becomes 1, 0, 3, 2, etc. Then the addresses are also generated in staggered order, so that the words go into the correct location in memory. In this way, the word order of loading and reading of data is always successively odd and even regardless of the size of the image.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.