Figure 1.36 Usage of P1 to establish data valid and data invalid states
(a) Starting pacing transfers at end of training pattern
See (2) Paced transfer training pattern for the description of starting a data valid state after a
training pattern.
(b) Starting pacing transfers with no training pattern
Before starting the DT DATA IN phase the TARG will wait at least two system deskew delays
after the SEL signal is negated before the first assertion of the REQ signal.
The DT DATA IN phase without training starts on the first assertion of REQ if the SEL is not
asserted.
The TARG begins pacing transfers only after meeting all the following:
a)
signal restrictions between information transfer phases;
b)
the signal restrictions between a RESELECTION phase and a DT DATA IN phase;or
c)
the signal restrictions between a SELECTION phase and a DT DATA OUT phase.
The TARG begins pacing transfers by:
1)
simultaneously with the assertion of REQ the TARG shall begin asserting and negating
P1 at twice the negotiated transfer period (e.g., 12,5 ns for fast-160);
2)
TARG asserts and negates P1 at least 8 times (e.g., (2 x 6,25 ns) x 8 = 100 ns at fast-
160); and
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