ADV7180
Table 29. HUE Function
SD_SAT_Cr[7:0], SD Saturation Cr Channel,
Address 0xE4 [7:0]
HUE[7:0]
0x00 (default)
0x7F
Description (Adjust Hue of the Picture)
Phase of the chroma signal = 0°
Phase of the chroma signal = −90°
Phase of the chroma signal = +90°
This register allows the user to control the gain of the Cr
channel only, which in turn adjusts the saturation of the picture.
0x80
Table 25. SD_SAT_Cr Function
SD_SAT_Cr[7:0] Description
DEF_Y[5:0], Default Value Y, Address 0x0C [7:2]
When the ADV7180 loses lock on the incoming video signal or
when there is no input signal, the DEF_Y[5:0] register allows
the user to specify a default luma value to be output. This value
is used under the following conditions:
0x80 (default)
0x00
0xFF
Gain on Cr channel = 0 dB
Gain on Cr channel = −42 dB
Gain on Cr channel = +6 dB
SD_OFF_Cb[7:0], SD Offset Cb Channel, Address 0xE1 [7:0]
•
If DEF_VAL_AUTO_EN bit is set to high and the ADV7180
has lost lock to the input video signal, this is the intended
mode of operation (automatic mode).
This register allows the user to select an offset for the Cb
channel only and to adjust the hue of the picture. There is a
functional overlap with the HUE[7:0] register.
•
The DEF_VAL_EN bit is set, regardless of the lock status of
the video decoder. This is a forced mode that may be
useful during configuration.
Table 26. SD_OFF_Cb Function
SD_OFF_Cb[7:0] Description
0x80 (default)
0x00
0xFF
0 offset applied to the Cb channel
−312 mV offset applied to the Cb channel
+312 mV offset applied to the Cb channel
The DEF_Y[5:0] values define the six MSBs of the output video.
The remaining LSBs are padded with 0s. For example, in 8-bit
mode, the output is Y[7:0] = {DEF_Y[5:0], 0, 0}.
For DEF_Y[5:0], 0x0D (blue) is the default value for Y.
Register 0x0C has a default value of 0x36.
SD_OFF_Cr [7:0], SD Offset Cr Channel, Address 0xE2 [7:0]
This register allows the user to select an offset for the Cr channel
only and to adjust the hue of the picture. There is a functional
overlap with the HUE[7:0] register.
DEF_C[7:0], Default Value C, Address 0x0D [7:0]
The DEF_C[7:0] register complements the DEF_Y[5:0] value. It
defines the four MSBs of Cr and Cb values to be output if
Table 27. SD_OFF_Cr Function
SD_OFF_Cr[7:0]
0x80 (default)
0x00
Description
•
The DEF_VAL_AUTO_EN bit is set to high and the
ADV7180 cannot lock to the input video (automatic mode).
0 offset applied to the Cr channel
−312 mV offset applied to the Cr channel
+312 mV offset applied to the Cr channel
•
DEF_VAL_EN bit is set to high (forced output).
0xFF
The data that is finally output from the ADV7180 for the
chroma side is Cr[7:0] = {DEF_C[7:4], 0, 0, 0, 0}, Cb[7:0] =
{DEF_C[3:0], 0, 0, 0, 0}.
BRI[7:0], Brightness Adjust, Address 0x0A [7:0]
This register controls the brightness of the video signal. It
allows the user to adjust the brightness of the picture.
For DEF_C[7:0], 0x7C (blue) is the default value for Cr and Cb.
DEF_VAL_EN, Default Value Enable, Address 0x0C [0]
Table 28. BRI Function
BRI[7:0]
0x00 (default)
0x7F
Description
This bit forces the use of the default values for Y, Cr, and Cb.
Refer to the descriptions in the DEF_Y[5:0], Default Value Y,
Address 0x0C [7:2] and DEF_C[7:0], Default Value C, Address
0x0D [7:0] sections for additional information. In this mode,
the decoder also outputs a stable 27 MHz clock, HS, and VS.
Offset of the luma channel = 0IRE
Offset of the luma channel = +100IRE
Offset of the luma channel = –100IRE
0x80
HUE[7:0], Hue Adjust, Address 0x0B [7:0]
Setting DEF_VAL_EN to 0 (default) outputs a colored screen
determined by user-programmable Y, Cr, and Cb values when
the decoder free-runs. Free-run mode is turned on and off by
the DEF_VAL_AUTO_EN bit.
This register contains the value for the color hue adjustment. It
allows the user to adjust the hue of the picture.
HUE[7:0] has a range of 90°, with 0x00 equivalent to an
adjustment of 0°. The resolution of HUE[7:0] is 1 bit = 0.7°.
Setting DEF_VAL_EN to 1 forces a colored screen output
determined by user-programmable Y, Cr, and Cb values. This
overrides picture data even if the decoder is locked.
The hue adjustment value is fed into the AM color demodula-
tion block. Therefore, it only applies to video signals that contain
chroma information in the form of an AM-modulated carrier
(CVBS or Y/C in PAL or NTSC). It does not affect SECAM and
does not work on component video inputs (YPrPb).
Rev. A | Page 26 of 112
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