T13 E00164R0 Cable Detection Issues in D1410R1 Kent H. Pryor Quantum Corporation December 8, 2000 E00164R0

T13 E00164R0 Previous Cable Detection Issues Non-compliant PDIAG from Device 1. –40 conductor detected as 80 at host –80 conductor detected as 40 at device Intel system riser PCB could not accommodate host detection.

T13 E00164R0 Current Cable Detection Issues Host alternatives in different sections. Some methods required, others optional or “not recommended”. Combo method algorithm was incomplete. Combo method removed for wrong reason.

T13 E00164R0 Cable Detection Discussion Goals View side-by-side summary of methods. Consensus on overall strategy. Direction for any needed proposals.

T13 E00164R0 Combo method was in The host may sample CBLID- after a power-on or hardware reset in order to detect the presence or absence of an 80-conductor cable assembly by performing the following steps: –) The host shall wait until the power-on or hardware reset protocol is complete for all devices on the cable; –) If Device 1 is present, the host should issue IDENTIFY DEVICE or IDENTIFY PACKET DEVICE and use the returned data to determine that Device 1 is compliant with ATA-3 or subsequent standards. Any device compliant with ATA-3 or subsequent standards releases PDIAG- no later than after the first command following a power-on or hardware reset sequence and will not interfere with host detection of CBLID- in the next step. –) The host shall wait until after it has issued an IDENTIFY DEVICE or IDENTIFY PACKET DEVICE command to Device 1 before detecting the state of CBLID- in order to detect the presence or absence of an 80-conductor cable. –) If a device supporting Ultra DMA modes greater than 2 is present, the host shall use Word 93 bit 13 from the IDENTIFY DEVICE or IDENTIFY PACKET DEVICE data of that device to verify the presence of an 80- conductor cable. –NOTE  Older devices not in compliance with ATA-3 or subsequent standards may continue to assert this signal providing a false indication of the cable type. If the host detects that CBLID- is connected to ground, an 80-conductor cable assembly is installed in the system or device 1 was asserting PDIAG- when the state of CBLID- was detected. If a device supporting Ultra DMA modes greater than 2 is present in this condition, a value of 11 in Word 93 bits from that device when CBLID- is detected to be connected to ground at the host confirms the presence of an 80-conductor cable. A value of 10 from the device when CBLID- is detected to be connected to ground at the host indicates that an attached device 1 is driving PDIAG- and the cable type can not be determined. If the host detects that this signal is not connected to ground, an 80-conductor cable assembly is not installed in the system. For this result, the value of Word 93 bit 13 of a device supporting Ultra DMA modes greater than 2 may be 0 or 1 depending on host loading of CBLID-. See Annex B for a description of the non-standard device determination of cable type.

T13 E00164R0 D1410R1 specifications for host

T13 E00164R0 Cable Detection Alternatives A. No changes. B. Improve & restore combo method C. Require unspecified method in 6.7 and 8.45, move 3 possible methods to Annex B. D. Keep host detection in 6.7, move 2 alternate methods to Annex B. E. Require unspecified method in 6.7 and 8.45, remove alternate descriptions.