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-----Original Message----- From: Sherry, John [mailto:[EMAIL PROTECTED]] > >First case: >For the Request Sense Packet Command, I see that if a CRC error >is detected by the device during the transmission of sense data >that it should complete the command with the check condition >(STATUS register bit 0 = '1'). The device shall report a sense >key of 0xB {Command Aborted} (presumably in the ERROR register >bits 7 down to 4). Should the device also set the abort bit >(ERROR register bit 2) = '1'? No. The device did not abort the PACKET command. But I see ATAPI devices that always set ABRT=1 anytime they set ERR=1 (sorry, make that CHECK=1, SCSI devices don't get errors, they get check conditions!). In my opinion ABRT has meaning only up to the time the device receives the command packet data (the SCSI CDB). Any error after the command packet has been received must be a SCSI error (not an ATA/ATAPI error). >Second case: >For the non Request Sense Packet Commands, I see that if a CRC >error is detected by the device during the transmission of data >that it should complete the command with the check condition >(STATUS register bit 0 = '1'). The device shall report a sense >key of 0x4 {Hardware Error} (presumably in the ERROR register >bits 7 down to 4). Should the device also set the abort bit >(ERROR register bit 2) = '1'? Or SK=BH or pick any other SK that might be interpreted as a data transmission or communications error. Apparently ATAPI device designers are not reading ATA/ATAPI-x (so whats new there?) and they are just picking SK value at random to report ICRC errors (and many other errors too, they probably don't read the SCSI standards either). >If I understand things correctly the ICRC bit (ERROR register bit >7) should not be set by an ATAPI (Packet) device, is this >assumption correct. Once an ATAPI device has received the command packet (the SCSI CDB) the Error register changes definition. Bits 7-4 become the SK value and there is no ICRC bit to set! *** Hale Landis *** [EMAIL PROTECTED] *** *** Niwot, CO USA *** www.ata-atapi.com *** Subscribe/Unsubscribe instructions can be found at www.t13.org.
