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An Ata/pi device can be designed within the standard to remove the need to use INTRQ, especially for Pio transfers. The idea is that the host instead polls port x3F6 AlternateStatus to see when BSY clears. This works best if the host in question has a Pio accelerator that makes Pio polling as efficient for the host cpu as Dma is. But certainly, to try to operate without INTRQ is to fail ToTalkLikeWindows. Operating without INTRQ is accordingly a practice which breaks devices in the real world ... but this practice saves a pin on a chip, which can make the chip dramatically cheaper by reducing the package size. By the way, a host chip that does use INTRQ is not Necessarily more interoperable. More info is good only if used intelligently. To the degree to which BSY and INTRQ are redundant with one another, they can disagree. Tuning the chip to cope well when they do disagree is a dark art. Pat LaVarre x4402 >>> liman Munandar <[EMAIL PROTECTED]> 01/21/02 04:53PM >>> This message is from the T13 list server. Dear T13: Does anyone know where I can get more info on the use of the interrupt? The question I have is whether the INTRQ pin is optional or not. I have a design using a chip with ATA/ATAPI interface. The INTRQ pin was left open. I wonder if this is ok. Can an ATA/ATAPI device operate without any interrupt service? Thank you in advance. Regards, Liman Munandar Associate Engineer Dura Micro Subscribe/Unsubscribe instructions can be found at www.t13.org. Subscribe/Unsubscribe instructions can be found at www.t13.org.
