DRAM multiplexer
US5313624A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 14, 1991 |
| Grant date | May 17, 1994 |
| Priority date | — |
| Expiry date | May 14, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F13/287
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The present invention provides a system for supporting one or more memory requestors (CPU's and I/O DMA) accessing a plurality of DRAM memory banks. The present invention is a multiplexer that functions as a 16-bit slice of the interface between the CPU and a 64-bit slice of DRAM memory array. The invention includes an error correction (ECC) module, a 64-bit DRAM I/O channel, an 8-bit ECC "syndrome" I/O channel and an 8-bit slice of a DMA bus I/O channel. In a write operation, the CPU transmits data through the I/O channel to write the data to the DRAM. Each word is routed by the four-way multiplexer to one of the four memory registers. When the four registers have been filled with data words, the words are assembled into a multiple word burst and sent to the DRAM bank. The data is also passed through an error correction module. For a read operation, DRAM data is latched into the CPU register and transported to the CPU while the DRAM is potentially being accessed for another memory read.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.