Method and apparatus for data inversion in memory device
US7567467B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 15, 2004 |
| Grant date | Jul 28, 2009 |
| Priority date | — |
| Expiry date | Dec 17, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C2207/108
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The present invention is a method of writing information to a synchronous memory device by examining a present word of N bits to be written, where each bit has a high or low value. The present word is compared to a previous word also having N bits to identify the number of bit transitions from a low value to a high value of vice versa. The present bit is inverted when the number of transitions is greater than N/2. To avoid the need for having an extra bit accompany data bytes to indicate the presence or absence of inversion, the present invention takes advantage of a data mask pin that is normally unused during writing operations to carry the inversion bit. Non-inverted data is written directly into the memory device while inverted data is first inverted again before writing to storage locations, so that true data is stored in the memory device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.