DS92LV1023E_14 Datasheet, PDF (4/21 Pages) Texas Instruments – 30-66 MHz 10 Bit Bus LVDS Serializer

DS92LV1023E
SNLS187B – MARCH 2005 – REVISED APRIL 2013
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If a specific pattern is repetitive, the Deserializer could enter “false lock” - falsely recognizing the data pattern as
the clocking bits. We refer to such a pattern as a repetitive multi-transition, RMT. This occurs when more than
one Low-High transition takes place in a clock cycle over multiple cycles. This occurs when any bit, except DIN
9, is held at a low state and the adjacent bit is held high, creating a 0-1 transition. In the worst case, the
Deserializer could become locked to the data pattern rather than the clock. Circuitry within the DS92LV1224 can
detect that the possibility of “false lock” exists. The circuitry accomplishes this by detecting more than one
potential position for clocking bits. Upon detection, the circuitry will prevent the LOCK output from becoming
active until the potential “false lock” pattern changes. The false lock detect circuitry expects the data will
eventually change, causing the Deserializer to lose lock to the data pattern and then continue searching for clock
bits in the serial data stream. Graphical representations of RMT are shown in Figure 1 . Please note that RMT
only applies to bits DIN0-DIN8.
Powerdown
When no data transfer occurs, you can use the Powerdown state. The Serializer and Deserializer use the
Powerdown state, a low power sleep mode, to reduce power consumption. The Deserializer enters Powerdown
when you drive PWRDN and REN low. The Serializer enters Powerdown when you drive PWRDN low. In
Powerdown, the PLL stops and the outputs enter TRI-STATE, which disables load current and reduces supply
current to the milliampere range. To exit Powerdown, you must drive the PWRDN pin high.
Before valid data exchanges between the Serializer and Deserializer, you must reinitialize and resynchronize the
devices to each other. Initialization of the Serializer takes 510 TCLK cycles. The Deserializer will initialize and
assert LOCK high until lock to the Bus LVDS clock occurs.
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