Synchronous DMA burst transfer protocol having the peripheral device toggle the strobe signal such that data is latched using both edges of the strobe signal
US5758188A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 21, 1995 |
| Grant date | May 26, 1998 |
| Priority date | — |
| Expiry date | Nov 21, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F13/28
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A synchronous DMA burst transfer method is provided for transferring data between a host device and a peripheral drive device connected by an ATA bus. The method provides synchronous data transfer capability in an asynchronous system by having one device in charge of both a strobe signal and a data signal. When a host read or write command is delivered to the peripheral drive device, the peripheral device decides when to start the synchronous DMA burst. For a read command, the peripheral device requests the synchronous DMA burst then drives a data word onto the ATA bus after the host acknowledges that it is ready to begin the burst. After allowing time for the data signal to settle, the peripheral device toggles a strobe signal from a high state to a low state. The host sees the edge of the strobe signal at which time the host latches the data word on the bus. Additional data words can be driven on the bus and the strobe signal can be retoggled to latch the additional data words into the host. After all data words have been transferred, the strobe signal is returned to a high state so that it is ready to be used for another host command. By having the device which is sending the da…
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