www.ti.com
4.12.9 Video Display Field 1 Image Offset Register (VDIMGOFF1)
Video Display Registers
The video display field 1 image offset register (VDIMGOFF1) defines the field 1 image offset and specifies
the starting location of the displayed image relative to the start of the active display.
The image line counter (ILCOUNT) is reset to 1 on the first image line (when FLCOUNT =
VBLNKYSTOP1 + IMGVOFF1). If the NV bit is set, ILCOUNT is reset to 1 when FLCOUNT =
VBLNKYSTOP1 - IMGVOFF1. Display image pixels are output in field 1 beginning on the line where
ILCOUNT = 1. The default output values or blanking values are output during active lines prior to
ILCOUNT = 1. For a negative offset, IMGVOFF1 must not be greater than VBLNKYSTOP1. The field 1
active image must not overlap the field 2 active image.
The image pixel counter (IPCOUNT) is reset to 0 at the start of an active line image. Once ILCOUNT = 1,
image pixels from the FIFO are output on each line in field 1 beginning when FPCOUNT = IMGHOFF1. If
the NH bit is set, IPCOUNT is reset when FPCOUNT = FRMWIDTH - IMGHOFF1. The default output
values or blanking values are output during active pixels prior to IMGHOFF1.
The video display field 1 image offset register (VDIMGOFF1) is shown in
and described in
.
Figure 4-39. Video Display Field 1 Image Offset Register (VDIMGOFF1)
31
30
28
27
16
NV
Reserved
IMGVOFF1
R/W-0
R-0
R/W-0
15
14
12
11
0
NH
Reserved
IMGHOFF1
R/W-0
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 4-14. Video Display Field 1 Image Offset Register (VDIMGOFF1) Field Descriptions
Description
Bit
field
(1)
symval
(1)
Value
BT.656 and Y/C Mode
Raw Data Mode
31
NV
OF(value)
Negative vertical image offset enable bit.
DEFAULT
0
Not used.
NONE
NEGOFF
1
Display image window begins before the
Not used.
first active line of field 1. (Used for VBI
data output.)
30-28
Reserved
-
0
Reserved. The reserved bit location is always read as 0. A value written to this field
has no effect.
27-16
IMGVOFF1
OF(value)
0-FFFh
Specifies the display image vertical offset in lines from the first active line of field 1.
DEFAULT
0
15
NH
OF(value)
Negative horizontal image offset.
DEFAULT
0
Not used.
NONE
NEGOFF
1
Display image window begins before the
Not used.
start of active video. (Used for HANC
data output.)
14-12
Reserved
-
0
Reserved. The reserved bit location is always read as 0. A value written to this field
has no effect.
(1)
For CSL implementation, use the notation VP_VDIMGOFF1_field_symval.
132
Video Display Port
SPRUEM1 – May 2007