Video ram having an option of a full sam and a half sam
US5479393A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 20, 1994 |
| Grant date | Dec 26, 1995 |
| Priority date | — |
| Expiry date | Jun 20, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C7/1075
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A video RAM device which is easily manufactured to be compatible with a video system, irrespective of the type of video RAM controller used in the system. The video RAM is freely changeable in a manufacturing step to operate as either a half SAM device or as a full SAM device to conform to the type of video RAM controller used or current demand of customers of video RAM devices, depending upon an internal addressing condition. The video RAM device includes a serial access memory (SAM) and a random access memory (RAM) each having interleaved groups of memory cells which are interleaved with respect to a serial output sequence from the SAM. A first interleaved group is represented by memory cells having an address with a most significant bit being at one logic level, and a second interleaved group is represented by memory cells having an address with a most significant bit being at an opposite logic level. The video RAM device also includes a serial counter for generating serial addresses, and a group of transfer gates for transferring data between the RAM and the SAM.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.