User Manual

SCSI Commands Reference Manual, Rev. J 454
www.seagate.com Parameters for direct access devices
RESET bit
This bit controls the TX to C1, C2 and C3, and controls the reset function of IREC bits (see table 427).
FFE TAP 0, 1 / RX EYE HEIGHT AND RX EYE WIDTH (Read only)
The FFE Tap 0, 1 field shall contain the current (MODE SENSE) FFE Tap 0 and Tap 1 coefficient with the RESET bit is set to 0 and IREC Completed
bit set to 0. The RX Eye Height And RX Eye Width fields shall contain the current (MODE SENSE) RX eye height and RX eye width with IREC com-
pleted bit set to 1.
DFE COEFFICIENT 0 - 4 (Read only)
This field shall contain the current (MODE SENSE) DFE coefficient of the receiver. If the number of DFE coefficients is more than 5, then only the
first 5 coefficients shall be displayed.
HOST TRANSMITTER C1, C2 AND C3 RELATIVE SETTING (Read Only)
This field shall contain the user input (MODE SELECT) of the C1, C2 and C3 relative setting of host transmitter.
During the speed negotiation, the C1, C2 and C3 of the Host transmitter will be adjusted by Up or Hold or Down.
Keep track of the adjustment by each Up = +1, each Hold = 0 and each Down = -1, i.e. C1 is adjusted by 3 Up tics and 1 Down,
the relative Host C1 is 1+1+1-1 = 2.
Table 428 RESET and IREC bit function
RESET
(Mode
Select)
IREC
(Mode
Select)
IREC
Completed
Mode Sense data after Mode Select was executed
with different RESET bit and IREC bit settings.
0 0 0
n No change on current C1, C2, C3
n All FFE and DFE coefficients shall be updated
0 0 1
n Set IREC Completed bit to 1 when RX eye capture is completed
n IRC Margin shall be displayed
n RX eye height and eye width shall be displayed instead of RX FFE coefficients.
n All DFE coefficients shall be updated
1 0 Don’t
Care
n Set TX to C1, C2, C3 (no retrain)
n All FFE and DFE coefficients shall be updated
n After reset operation completed, Reset bit shall be set to 0,
IREC Completed bit shall be set to 0.
n All FFE and DFE coefficients shall be updated.
1 1 Don’t
Care
n No change on current C1, C2, C3
n Perform internal RX eye capture
n After RX eye capture completed,
Reset bit shall be set to 0 and IREC Completed bit shall be set to 1.
n IRC Margin shall be displayed
n RX eye height and eye width shall be displayed instead of RX FFE coefficients.
n All DFE coefficients shall be updated