Motorola Symbol SE4400, Руководство по интеграции

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5-7
Application Notes
Table 5-1. Mode 3 Signal Function Summary
Signal
Name
I/O Function
Significance of
Negative Edge
Significance of
Positive Edge
Comment
EXSFT I Sets exposure
time.
Begins frame
transfer.
Causes the CCD
to begin exposing. Causes the CCD to
stop exposing.
Begins transfer of
pixel data from that
exposure (frame
transfer).
The period
between
successive positive
edges is called a
frame.
VREF O Signifies when
valid vertical
lines are being
read. Reading of valid
vertical lines is
complete. Reading of valid
vertical lines has
begun.
EXHT I External
horizontal clock. Triggers the
reading of the next
horizontal line of
the CCD. None The period of
EXHT is known as
a line time and is
denoted "H".
HREF O Signifies when
valid part of
horizontal line is
being read. Reading of valid
part of line is
complete. Reading of valid part
of line has begun.
PCLK O Pixel clock. None Indicates the 8-bit
pixel data is available
to be read out. The period of PCLK
is denoted "T".