Byte accessible memory interface using reduced memory control pin count
US6055594A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 24, 1998 |
| Grant date | Apr 25, 2000 |
| Priority date | — |
| Expiry date | Aug 24, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F13/1678
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A byte accessible memory interface circuit using a reduced set of memory control signals. The present invention includes an interface circuit having a reduced set of memory control signals for performing word length reads and writes to an external memory module containing a plurality of integrated circuit (IC) memory chips. The interface circuit contains a respective multiplexer and a respective register circuit for each byte of the word length data. The multiplexers select a byte of data from either an on-chip data bus or from a bus carrying data read from the external memory module. To perform a full length word write, the data from the on-chip bus is loaded into the registers (via the multiplexers) and then written to the memory module. To perform a partial length word write, a pre-read operation is performed at the target address and a word length data is loaded into the registers. The new data is then received over the on-chip data bus and routed by the multiplexers into the byte locations to be changed. The properly merged data is then written as a full length word to the memory module. To perform a full length word read, a word of data is loaded into the byte registers and t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.