Cable Detection Issues in D1410R1

About This Presentation

Title:

Cable Detection Issues in D1410R1

Description:

Direction for any needed proposals. T13 E00164R0. Combo method was in 5.2.11. The host may sample CBLID- after a power-on or hardware reset in order to detect ... – PowerPoint PPT presentation

Number of Views:98

Avg rating:3.0/5.0

Slides: 8

Provided by: kent158

Category:

more less

Transcript and Presenter's Notes

Title: Cable Detection Issues in D1410R1

1
Cable Detection Issues in D1410R1

Kent H. Pryor
Quantum Corporation
December 8, 2000
E00164R0

2
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.

3
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.

4
Cable Detection Discussion Goals

View side-by-side summary of methods.
Consensus on overall strategy.
Direction for any needed proposals.

5
Combo method was in 5.2.11

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 14-13 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.

6
D1410R1 specifications for host
7
Cable Detection Alternatives

A. No changes.
B. Improve restore combo method 5.2.11.
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.

Write a Comment

User Comments (0)