STV9937 datasheet(30/49 Pages) STMICROELECTRONICS

30 / 49 page

Picture BooSTTM

STV9937

30/49

7Picture BooSTTM

Picture BooSTTM allows images to be boosted either within a window, a screen area or over the

entire screen. To perform this function, the STV9212 preamplifier is required as well as the Picture

BooSTTM software which sends the window or screen area coordinates (X1, X2,Y1,Y2) to the RGB

video channels.

The Picture BooSTTM system embedded in the STV9937 includes:

●

The RGB Comparator

●

The Coordinate Decoder

●

The Control and Data registers

The STV9937 computes the data received on the RGB channel and generates a BooST signal

which is then sent to the STV9212. The coordinates can be received through the I²C bus by the

MCU as well.

The STV9937 also includes three 8 bits register used to store data received by RGB.

7.1

Video RGB Input Stage

The input stage is a triple analog-digital buffer for the video RGB inputs.

●

The input voltage range is 0 to 0.7 V

●

The inputs have to be supplied through a serial capacitor (100nF)

●

The input RGB must be set to ‘0’ during the horizontal sync.

The input stage includes a clamping function using the Hsync signal to fix the DC level of inputs.

The input stage is configured by three control bits; THCTL, CLP and ENCL as shown in Figure 37.

Figure 13: Hsync Clamping Function

THTCL

ENCL

HSYNC

CLP

AND

100nF

STV9937 Fiches technique(PDF) 30 Page - STMicroelectronics