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Table 3–6. BT.656 and Y/C Mode Capture Operation (Continued)
VCxCTL Bit
CON
FRAME
CF2
1
0
1
1
0
1
1
1
0
1
1
0
1
1
1
1
1
1
3.4.2
Vertical Synchronization
The video port uses a capture window to determine which incoming data samples
to capture in each field. The capture module uses a vertical line counter
(VCOUNT) to track which video line is currently being received. The line count-
er is compared to the appropriate capture window start (VCYSTART1 or
VCYSTART2) and stop (VCYSTOP1 or VCYSTOP2) values for the current
field to determine if the current line is within the capture window. In order to
correctly align the capture window within the field, the capture module must
know which line should correspond to the first line of the field, that is, when to
reset the line counter. This point may vary depending on the type of capture
being performed and the signals available for vertical synchronization. The
video port allows the vertical counter reset trigger to be determined by
programming the EXC and VRST bits in VCxCTL. The encoding of these bits
is shown in Table 3–7. Note that VModes 2 and 3 are only available for single
channel operation (channel A).
SPRU629
CF1
Operation
0
Continuous field 2 capture. Capture only field 2. F2C is set after field 2
capture and causes CCMPx to be set (CCMPx interrupt can be
disabled). The video port continues capturing field 2 fields, regardless
of the state of F2C.
1
Reserved
0
Continuous frame capture. Capture both fields. FRMC is set after
field 2 capture and causes CCMPx to be set (CCMPx interrupt can be
disabled). The video port continues capturing frames, regardless of the
state of FRMC.
1
Continuous progressive frame capture. Capture field 1. FRMC is set
after field 1 capture and causes CCMPx to be set (CCMPx interrupt can
be disabled). The video port continues capturing frames, regardless of
the state of FRMC. (Functions identically to continuous field 1 capture
mode except the FRMC bit is used instead of the F1C bit.)
0
Reserved
1
Reserved
BT.656 and Y/C Mode Field and Frame Operation
Video Capture Port
3-19
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