Direct memory access apparatus for transferring a block of data having discontinous addresses using an address calculating circuit
US6108722A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 13, 1996 |
| Grant date | Aug 22, 2000 |
| Priority date | — |
| Expiry date | Sep 13, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F13/28
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method and arrangement for a dma transfer mode having multiple transactions is provided. The invention generates a set of transaction entries for a DMA transfer each of which contains information related to the address and command instruction of a transaction. The transaction entries are stored in an address/cmd-output-FIFO. The invention negotiates for the control of the system bus. Upon gaining control of the bus, the commands and address relate to each transaction are sequentially place on the system bus. If the transaction is a read operation, data received back from the system bus is first stored in a data-in-FIFO before being sent to the desired destination. If the transaction is a write operation, the data to be transferred is first stored in a data-out-FIFO before being timely place on the system bus for transferring to the desired destination. In either case, the number of data words transferred is monitored to determine when a transaction is complete. The number of transactions carried out is also monitored to determine when a DMA transfer is complete.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.