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I see where you're going now. I'm thinking I agree with you, but I'm going over this with the proverbial fine-toothed comb again. Looking at the draft of ATA8-APT, it appears that I'd flagged this while I was going over the state machines. -----Original Message----- From: Michael G. Farley [mailto:[EMAIL PROTECTED] Sent: Tuesday, January 31, 2006 11:05 AM To: Mark Overby Cc: [email protected] Subject: Re: [t13] ATA/ATAPI-6 HPIOI2:HPIOI2 Transition I'm sorry, I meant to say the device Data register. I appreciate your quick response. Do you have any comments on my email after substituting "device Data register" in for "device Drive register"? I agree with your comments completely. Where I see the discrepancy is: During the HPIOI2: Transfer_Data state, you should not be reading any register except the device Data register. So why would you read the device Status register? All the other figures and similar protocol states (PIO Data-out, HPIOO1: Transfer_Data state) seem to conflict with the HPIOI2:HPIOI2 transition's text description. --Mike Mark Overby wrote: > The DRQ bit is located in the status register. There is no drive > register. If you mean the device (old dev/head register), that would be > the wrong register as well. > > In order to know that the DRQ block has been completed, you have to go > back, wait for BSY to drop at the device, and then continue transferring > data. (Assuming there is more data to transfer). Note - that BSY could > go high and drop again before your host can read the status register, so > the host loops through HPIOI2->HPIOI1->HPIOI2 very quickly and you won't > actually spend any time there. > > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of > Michael G. Farley > Sent: Tuesday, January 31, 2006 10:19 AM > To: [email protected] > Subject: [t13] ATA/ATAPI-6 HPIOI2:HPIOI2 Transition > > This message is from the T13 list server. > > > To whom it may concern, > > I work with Green Hills Software based in Santa Barbara, CA. I've been > studying the ATA/ATAPI-6 Standard, and I think I've found a discrepancy. > In the Transition from HPIOI2 to HPIOI2, shouldn't the first line > read, "When the host has read the device Drive register..."? > > The standard instead reads, "When the host had read the device Status > register". > > Transition HPIOI2:HPIOI2: When the host has read the device status > register and the DRQ data block transfer has not completed, then the > host shall make a transition to the HPIOI2: Transfer_Data state. > > I noticed that the latest ATA/ATATPI-7 Standard reads the same as the > ATA/ATAPI-6 Standard. > > When I looked into the Figure 25 and 26, they read "device Drive > register" and not "device Status register". > > You are the only email address I could find in the Standard. If you are > not the person I should be contacting, please let me know who is. > > --Mike Farley > >
