DS90CR486_06 Datasheet, PDF (14/18 Pages) National Semiconductor (TI) – 133MHz 48-Bit Channel Link Deserializer (6.384 Gbps)

FIGURE 10. Deskew Configuration Setup Chart
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CONFIGURATION 1
DS90CR481/483 and DS90CR484 with DC Balance ON
(BAL=High, 33MHz to 80MHz) − The DS_OPT pin at the input
of the transmitter DS90CR481/483 must be applied low for a
minimum of four clock cycles in order for the receiver to com-
plete the deskew operation. The input to the DS_OPT pin can
be applied at any time after the PLL has locked to the input
clock frequency. In this particular setup, the "DESKEW" pin
on the receiver DS90CR484 must set High.
CONFIGURATION 2
DS90CR481/483 and DS90CR486 with DC Balance ON
(BAL=High, CON1=High, 66MHz to 112MHz) − The DS_OPT
pin at the input of the transmitter DS90CR481/483 can be set
to High OR Low when power up. The period of this input to
the DS_OPT pin must be at least 20ms (TX and RX PLLs lock
time) plus 4096 clock cycles in order for the receiver to com-
plete the deskew operation. The "DESKEW" and CON1 pins
on the receiver DS90CR486 must be tied to High for this set-
up.
CONFIGURATION 3
DS90CR481/483 and DS90CR486 with DC Balance OFF
(BAL=Low, CON1=High, 66MHz to 112MHz) − The input to
the DS_OPT pin of the transmitter DS90CR481/483 in this
configuration is completely ignored by the transimitters. In or-
der to initialize the deskew operation on the receiver
DS90CR486, data and clcok must be applied to the transimit-
ter when power up. The "DESKEW" and CON1 pins on the
receiver DS90CR486 must be tied to High for this setup.
CONFIGURATION 4
DS90CR485 and DS90CR484 with DC Balance ON
(BAL=High, 66MHz to 80MHz) − The DS_OPT pin at the input
of the transmitter DS90CR485 must be applied low for a min-
imum of four clock cycles in order for the receiver to complete
the deskew operation. The input to the DS_OPT pin can be
applied at any time after the PLL has locked to the input clock
frequency. In this setup, the "DESKEW" pin on the receiver
DS90CR484 must set High.
CONFIGURATION 5
DS90CR485 and DS90CR486 with DC Balance ON (BAL=Hi-
igh, CON1=High, 66MHz to 133MHz) − The DS_OPT pin at
the input of the transmitter DS90CR485 can be set to High
OR Low when power up. The period of this input to the
DS_OPT pin must be at least 20ms (TX and RX PLLs lock
time) plus 4096 clock cycles in order for the receiver to com-
plete the deskew operation. The "DESKEW" and CON1 pins
on the receiver DS90CR486 must set High.
CONFIGURATION 6
DS90CR485 and DS90CR486 with DC Balance OFF
(BAL=Low, CON1=High, 66MHz to 133MHz) −The input to
the DS_OPT pin of the transmitter DS90CR485 in this con-
figuration is completely ignored. In order to initialize the
deskew operation on the receiver DS90CR486, data and
clcok must be applied to the transimitter when power up. The
"DESKEW" and CON1 pins on the receiver DS90CR486 must
set High.
DESKEW NOT SUPPORTED
Deskew function is NOT supported in these configuration se-
tups. The deskew feature is only supported with DC Balance
ON (BAL=High) for DS90CR484. Note that the deskew func-
tion in the DS90CR486 works in both DC Balance and NON-
DC Balance modes.
Note 11: For more details on Deskew operation, please refer to the
"Application Information" section.
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