Fujitsu MBA3300 NP SERIES, Technical Manual

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50 C141-C015
(44) De-skewed data valid window
The minimum difference in time allowed between the rising or falling edge of a "1010..." pattern
on the DATA BUS or DB(P1) and its clocking signal on the ACK or REQ signal as measured at
their zero-crossing points after skew compensation is applied by the receiver without allowing any
error in the received data (see Fig.1-17). The de-skewed data valid window shall be equal to:
± [(data transfer period) - (residual skew error) - (strobe offset tolerance) - (clock jitter) - (receiver
amplitude skew) - (chip noise) - (system noise at receiver) - (receiver asymmetry)] / 2.
Figure 1.17 Receiver de-skew parameters
(45) Skew 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.
(46) Strobe offset tolerance
The time tolerance of centering the compensated REQ or ACK strobe in the transfer period during
the training pattern.
(47) Flow control receive hold time
The maximum time required by the SCSI INIT port between the assertion of the REQ signal
corresponding to the last iuCRC transfer of a SPI data stream information unit and the changing of
the P_CRCA signal.