Datasheet

Rev. 0 | Page 36 of 72 | June 2010
ADSP-21469
Link Ports
Calculation of link receiver data setup and hold relative to link
clock is required to determine the maximum allowable skew
that can be introduced in the transmission path length differ-
ence between LDATA and LCLK. Setup skew is the maximum
delay that can be introduced in LDATA relative to LCLK:
(setup skew = t
LCLKTWH
min – t
DLDCH
– t
SLDCL
). Hold skew is
the maximum delay that can be introduced in LCLK relative to
LDATA: (hold skew = t
LCLKTWL
min – t
HLDCH
– t
HLDCL
).
Table 32. Link Ports—Receive
Parameter Min Max Unit
Timing Requirements
t
SLDCL
Data Setup Before LCLK Low 0.5 ns
t
HLDCL
Data Hold After LCLK Low 1.5 ns
t
LCLKIW
LCLK Period t
LCLK
(6 ns) ns
t
LCLKRWL
LCLK Width Low 2.6 ns
t
LCLKRWH
LCLK Width High 2.6 ns
Switching Characteristics
t
DLALC
LACK Low Delay After LCLK Low
1
512ns
1
LACK goes low with t
DLALC
relative to rise of LCLK after first byte, but does not go low if the receiver's link buffer is not about to fill.
Figure 22. Link Ports—Receive
LDAT7–0
LCLK
LACK (OUT)
t
HLDCL
t
SLDCL
IN
t
LCLKRWH
t
LCLKRWL
t
LCLKIW
t
DLALC