Datasheet

ADSP-21060/ADSP-21060L/ADSP-21062/ADSP-21062L/ADSP-21060C/ADSP-21060LC
Rev. F | Page 39 of 64 | March 2008
Link Ports —2 × CLK Speed Operation
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 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
Calculations made directly from 2 speed specifications will
result in unrealistically small skew times because they include
multiple tester guardbands.
Note that link port transfers at 2× CLK speed at 40 MHz
(t
CK
= 25 ns) may fail. However, 2× CLK speed link port trans-
fers at 33 MHz (t
CK
= 30 ns) work as specified.
Table 25. Link Port Service Request Interrupts:1u and 2u Speed Operations
5 V 3.3 V
Unit
Parameter Min Max Min Max
Timing Requirements
t
SLCK
LACK/LCLK Setup Before CLKIN Low
1
10 10 ns
t
HLCK
LACK/LCLK Hold After CLKIN Low
1
22ns
1
Only required for interrupt recognition in the current cycle.
Table 26. Link Ports—Receive
5 V 3.3 V
Unit
Parameter Min Max Min Max
Timing Requirements
t
SLDCL
Data Setup Before LCLK Low 2.5 2.25 ns
t
HLDCL
Data Hold After LCLK Low 2.25 2.25 ns
t
LCLKIW
LCLK Period (2u Operation) t
CK
/2 t
CK
/2 ns
t
LCLKRWL
LCLK Width Low
1
4.5 5.25 ns
t
LCLKRWH
LCLK Width High
2
4.25 4 ns
Switching Characteristics
t
DLAHC
LACK High Delay After CLKIN High
3
18 + DT/2 28.5 + DT/2 18 + DT/2 29.5 + DT/2 ns
t
DLALC
LACK Low Delay After LCLK High
4
616616ns
1
For ADSP-21060L, specification is 5 ns min.
2
For ADSP-21062, specification is 4 ns min, for ADSP-21060LC, specification is 4.5 ns min.
3
LACK goes low with t
DLALC
relative to rise of LCLK after first nibble, but does not go low if the receiver’s link buffer is not about to fill.
4
For ADSP-21060L, specification is 6 ns min, 18 ns max. For ADSP-21060C, specification is 6 ns min, 16.5 ns max. For ADSP-21060LC, specification is 6 ns min, 18.5 ns max.