FIN24A Datasheet, PDF (9/20 Pages) Fairchild Semiconductor – Low Voltage 24-Bit Bi-Directional Serializer/Deserializer with Multiple Frequency Ranges (Preliminary)

Application Mode Diagrams (Continued)
Preliminary
FIGURE 9. Unidirectional Serializer and Deserializer
FIGURE 10. Multiple Units, Unidirectional Signals in Each Direction
Figure 10 shows a half duplex connectivity diagram. This
connectivity allows for two unidirectional data streams to
be sent across a single pair of SerDes devices. Data will be
sent on a frame by frame basis. For this mode of operation
to work there needs to be some synchronization between
when the Camera sends its data frame and when the LCD
sends its data. One option for this is to have the LCD send
data during the camera blanking period. External logic may
need to be provided in order for this mode of operation to
work.
Devices will alternate frames of data controlled by a direc-
tion control and a direction sense. When DIRI, on the right-
hand FIN24A is HIGH, data will be sent from the Camera to
the Camera interface at the base. When DIRI, on the right-
hand FIN24A goes LOW data will be sent from the base-
band process to the LCD. The direction is then changed at
DIRO on the right-hand FIN24A indicating to the left-hand
FIN24A to change direction. Data will be sent from the
Base LCD Unit to the LCD. The DIRO pin on the left-hand
FIN24A is used to indicate to the base control unit that the
signals are changing direction and the LCD is now avail-
able to be sent data. DIRI on the right-hand FIN24A could
typically use a timing reference signal such as VSYNC
from the camera interface to indicate direction change. A
derivative of this signal may be required in order to make
sure that no data is lost on the final data transfer.
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