DS92LX1621 Datasheet, PDF (36/44 Pages) National Semiconductor (TI) – 10 - 50 MHz Channel Link III Serializer and Deserializer with Embedded Bi-Directional Control Channel

FIGURE 31. BIST Timing Diagram
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Step 3: Stop at SPEED BIST by turning off BIST mode in the
Deserializer to determine Pass/Fail.
To end BIST, the system must pull BISTEN pin of the Dese-
rializer LOW. The BIST duration is fully defined by the BIS-
TEN width and thus the Bit Error Rate is determined by how
long the system holds BISTEN HIGH.
FIGURE 32. BIST BER Calculation
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For instance, if BISTEN is held HIGH for 1 second and the
PCLK is running at 43 MHz with 16 bpp, then the Bit Error
Rate is no better than 1.46E-9.
Step 4: Place system in Normal Operating Mode by disabling
BIST at the Serializer.
Once Step 3 is complete, AT SPEED BIST is over and the
Deserializer is out of BIST mode. To fully return to Normal
mode, apply Normal input data into the Serializer.
Any PASS result will remain unless it is changed by a new
BIST session or cleared by asserting and releasing PDB. The
default state of PASS after a PDB toggle is HIGH.
It is important to note that AT SPEED BIST will only determine
if there is an issue on the link that is not related to the clock
and data recovery of the link (whose status is flagged with
LOCK pin).
LVCMOS VDDIO OPTION
1.8V or 3.3V SER Inputs and DES Outputs are user config-
urable to provide compatibility with 1.8V and 3.3V system
interfaces.
REMOTE WAKE UP (Camera Mode)
After initial power up, the SER is in a low-power Standby
mode. The DES (controlled by host controller) 'Remote Wake-
up' register allows the DES side to generate a signal across
the link to remotely wake-up the SER. Once the SER detects
the wake-up signal, the SER switches from Standby mode to
active mode. In active mode, the SER locks onto PCLK input
(if present), otherwise the on-chip oscillator is used as the in-
put clock source. Note the host controller should monitor the
DES LOCK pin and confirm LOCK = H before performing any
I²C communication across the link.
For Remote Wake-up to function properly:
• The chipset needs to be configured in Camera mode: SER
M/S = 0 and DES M/S = 1
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