Fujitsu MBA3073 SERIES Technical Manual page 95

If the retain training information is enabled and a port changes from a INIT to a TARG that
TARG shall retrain if the saved training configuration values were saved while the port was a
INIT.
The receiving SCSI device shall use some or all elements of the training pattern to achieve
deskewing. The transmitting SCSI device shall not make an intentional shift in relative timing
between the data bus signals and the REQ or ACK signal during the DT data phase.
Note :
The requirement to not intentionally change relative timing does not include the effects of ISI,
noise, or jitter.
The training pattern consists of three sections; A, B, and C. Each section contains a different
pattern that may be used to train circuits within a receiver.
(a) DT DATA IN phase training pattern
The TARG indicates a training pattern is going to occur on a DT DATA IN phase by:
1) Releasing SEL for a minimum of two system deskew delays;
2) asserting the SEL signal a minimum of two system deskew delays; and
3) then asserting the REQ signal.
The TARG begins the section A of its training sequence by transmitting the following training
pattern:
Start of section A:
1) if precompensation is enabled then set the drivers to the strong driver state;
2) simultaneously assert REQ, P1, P_CRCA, and DB(15-0) signals;
3) wait the equivalent of 32 transfer periods (e.g., 200 ns at fast-160);
4) simultaneously negate REQ, P1, P_CRCA, and DB(15-0) signals;
5) wait the equivalent of 32 transfer periods;
6) set precompensation to negotiated state;
7) negate SEL signal;
8) simultaneously assert and negate REQ, P1, P_CRCA, and DB(15-0) signals at the
negotiated transfer period 64 times, (e.g., (2 x 6,25 ns) x 64 = 800 ns at fast-160);
Start of section B:
1) wait the equivalent of 192 transfer periods from the first assertion of REQ in step 2 of
section A (e.g., 1200 ns at fast-160);
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