Seagate Ultra 320, Ultra 160 Skew correction range, Strobe offset tolerance, System deskew delay

pensation.

2.5.49Skew correction range

The minimum skew correction capability of the receiver of a signal on the DATA BUS or DB(P1) relative to the ACK or REQ signal as measured at the receiver’s connector. The skew correction range shall be equal to:

+/– [(transmitter chip skew) + (cable skew) + (two times trace skew)]

relative to the corresponding ACK or REQ clock signal for that transition. Receiver chip skew is not included, as it is internal to the receiver.

2.5.50Strobe offset tolerance

The time tolerance of centering the compensated REQ or ACK strobe in the transfer period during the training pattern.

2.5.51System deskew delay

The minimum time that a SCSI device should wait after receiving a SCSI signal to ensure that asynchronous transfers at the same time are valid. The system deskew delay shall not be applied to the synchronous trans- fers or paced transfers.

2.5.52System noise at launch

The maximum time shift of SCSI bus signals caused by system noise at the transmitter (e.g., noise caused by current changes in the voice coil) measured at the transmitting SCSI device connector.

2.5.53System noise at receiver

The maximum time shift of SCSI bus signals caused by system noise at the receiver (e.g., noise caused by current changes in the voice coil) measured at the receiving SCSI device connector not including the time shift from the system noise at launch.

2.5.54Time asymmetry

The maximum time difference between the asserted and negated signal for data, REQ, or ACK transitions that are intended to be equidistant.

2.5.55Transmit assertion period

The minimum time that a SCSI target port shall assert the REQ signal while using synchronous transfers or paced transfers, provided it is not transitioning P_CRCA during data group transfers. Also, the minimum time that a SCSI initiator port shall assert the ACK signal while using synchronous transfers or paced transfers.

2.5.56Transmit hold time

For ST data transfers, the minimum time provided by the transmitting SCSI device between the assertion of the REQ signal or the ACK signal and the changing of the Data Bus, DB(P_CRCA), and/or DB(P1) while using synchronous data transfers. For DT data transfers, the minimum time provided by the transmitting SCSI device between the transition of the REQ signal or the ACK signal and the changing of the Data Bus, DB(P_CRCA), and/or DB(P1).

2.5.57Transmit ISI compensation

The effective reduction in worst-case ISI timing shift provided by the transmitting SCSI device as seen at the receiving SCSI device connector.

2.5.58Transmit negation period

32 Parallel SCSI Interface Product Manual, Rev. A )