FIN12AC_08 Datasheet, PDF (9/21 Pages) Fairchild Semiconductor – Low-Voltage 12-Bit Bi-Directional Serializer/Deserializer with Multiple Frequency Ranges

STROBE Pass-Through Mode
For some applications, it is desirable to pass a word
clock across a differential signal pair in the opposite
direction of serialization. The FIN12AC supports this
mode of operation.
For the deserializer:
1. DIRI = LOW
2. CKREF = LOW
3. Word clock should be connected to the STROBE.
This passes the STROBE signal out the CKSO port.
For the serializer:
1. Connect CKSO of the deserializer to CKSI of the
serializer.
2. CKSI passes the signal to CKP.
When PLL-bypass mode is used, the bit clock toggles on
the CKP signal.
Table 2. Control I/O
Mode Number
0
1, 2, 3
1, 2, 3
DIRI
x
0
1
DIRO
CKSO
CKP
Mode of Operation
Z
Z
Z
Power Down Mode: S2 = 0, S1 = 0
1
CKSO = STROBE
Deserializer
Output STROBE
Deserializer: Any active mode
0
Serializer
Output Bit Clock
CKSI
Serializer: Any active mode
Flex Circuit Design Guidelines
The serial I/O information is transmitted at a high serial rate. Care must be taken implementing this serial I/O flex cable.
The following best practices should be used when developing the flex cabling or Flex PCB:
■ Keep all four differential wires the same length.
■ Allow no noisy signals over or near differential serial wires. Example: No LVCMOS traces over differential wires.
■ Use only one ground plane or wire over the differential serial wires. Do not run ground over top and bottom.
■ Do not place test points on differential serial wires.
■ Use differential serial wires a minimum of 2cm away from the antenna.
© 2006 Fairchild Semiconductor Corporation
FIN12AC Rev. 1.1.2
9
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