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This proposal was at the end of my previous message but just so that it is not lost in your email in-box, here is just the proposal. Comments requested, especially from host adapter folks. Hale's proposal follows: Should Hale get a document number??? Pat wants a Byte Count for each DMA data burst just as we have Byte Count for each PIO DRQ data blocks. This BC must be transmitted from the device to the host at some point in each DMA data burst. On the host side these BC values must be added up and made available to the host software. Lets assume that we are adding this feature to U-DMA because it is the only DMA we really want people using in the future (SW DMA has been obsolete for years, and not supported by ATA hosts for years; MW DMA probably should be made obsolete sometime soon). OK? How about this? For U-DMA we define a scheme where the CRC is replaced by this BC value? Or do we need to define an entirely new DMA protocol (how about Enhanced Ultra DMA?) that has not only the CRC but the BC value? We need to find a way for the device to send the BC to the host and still allow the host to send the CRC to the device. Any ideas? *** Hale Landis *** www.ata-atapi.com ***
