Clamp And Gain; Figure 69: Esdp Block Diagram - Analog Devices Advantiv ADV7604 Hardware Manual

Input Input
Video Video
Clamp Clamp ADC ADC
(x3) (x3) (x3) (x3)
DDS DDS
XTAL XTAL
PLL PLL Clock Clock
Generator Generator
Existing AFE Existing AFE
9.4

Clamp and Gain

ESDP modes use digitally controlled analog (current source) clamping to place the back porch region
of the video signal at a target ADC code chosen to maximize the range of the video signal within the
ADC (target 12-bit code of 1434 for Y, R, G, and B signals and 12-bit code 2048 for U and V input
signals). This is followed by digital fine clamping which sets the back porch (or optionally the
pedestal) position to signed code 0, allowing the video signal to be gained without affecting the blank
level of the video signal.
The gain of the video signal can be manually programmed using Y_GAIN_MAN[12:0] and
C_GAIN_MAN. Additional gain controls in CP core are also available. A fixed offset is optionally
added after the gain to set the required output blanking level.
Y_GAIN_MAN[12:0] Luma Manual Gain , ESDP Map, Address 0x03, [4:0]; Address 0x04, [7:0]
Function
Y_GAIN_MAN[12
:0]
xxxx xxxx xxxxx
0x400
C_GAIN_MAN[12:0] Chroma Manual Gain , ESDP Map, Address 0x05, [4:0]; Address 0x06,
[7:0]
Function
C_GAIN_MAN[12
:0]
xxxx xxxx xxxx
0x400
Rev. F August 2010
Y/G Y/G Line Locked Data Line Locked Data
Pb/B Pb/B
Pr/R Pr/R
I²C I²C
Sync Slicing Sync Slicing
Control Control
Sliced Sync Sliced Sync
Clamp Clamp
Control Control
LLC LLC
Fine Sync Fine Sync
Detection Detection
Freq Freq
Word Word Line Locking Line Locking
Digital PLL Digital PLL

Figure 69: ESDP Block Diagram

Description
Manual gain applied to the Y channel. The range of the gain applied is
[0:4]. 0x400 corresponds to a gain of 1.
Default value
Description
Manual gain applied to the U and V channels. The range of the gain
applied is [0:4]. 0x400 corresponds to a gain of 1.
Default value
VSync VSync
Extraction Extraction
480i/480p 480i/480p
576i/576p 576i/576p
Detection Detection
Non Standard Non Standard
Detection Detection
ESDP ESDP
220
Y/G Y/G
Pb/B Pb/B
Pr/R Pr/R
CP Core CP Core
VS VS
FLD FLD
HS HS
LLC LLC
ADV7604
Y/G Y/G
Pb/B Pb/B
Pr/R Pr/R
VS VS
FLD FLD
HS HS
LLC LLC