DDP3310B datasheet(6/60 Pages) MICRONAS

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DDP 3310B

ADVANCE INFORMATION

Micronas

2. Functional Description

2.1. Display Part

The display part converts the digital YCrCb to analog

RGB (see Fig. 2–7) and provides contrast and satura-

tion adjustment. In case of YCrCb 4:1:1 an interpola-

tion filter is used, which converts the digital input signal

to YCrCb 4:2:2 standard. The 4:2:2 YCrCb signal is

processed by the horizontal scaler. In the luminance

processing path, a variety of features, such as

dynamic peaking and soft limiting, are provided. In the

chrominance path, the CrCb signals are converted to

4:4:4 format and filtered by a color transient improve-

ment circuit. The YCrCb signal is converted by a pro-

grammable matrix to RGB color space.

2.1.1. Input Interface

The data inputs Y0…Y7 and C0…C7 are clocked with

the external clock LLC2. The clock frequency is select-

able for 27 or 32 MHz. A clock generator converts the

different external line-locked clock rates to a common

internal sample rate of appr. 40.5 MHz in order to pro-

vide a fix bandwidth for all digital filters. The horizontal

scaler is used for conversion of scan rate and non-lin-

ear aspect ratio. The horizontal sync puls at the HS pin

should be an active video signal, which is not vertically

blanked.

The input interface signals are

– external clock (LLC2)

– luma / chroma inputs (Y0…Y7 / C0…C7)

– horizontal sync (HS) / vertical sync (VS, VS2)

2.1.2. Horizontal Scaler

The scaler block allows linear or non-linear horizontal

scaling of the digital input video signal in the range of

0.25 to 4. Non-linear scaling, also called “panorama

vision”, provides a geometrical distortion of the input

picture. It is used to fit a picture with 4:3 format on a

16:9 screen by stretching the picture geometry at the

borders. The inverse effect can be produced by the

scaler, also. The scaler consists of a programmable

decimation and interpolation filter and a 1/2H FIFO

memory.

A summary of scaler modes is given in Table 2–1.

2.1.3. Luma Processing

The blacklevel of the input signal is assumed to be 16

(ITU-R standard). The luminance signal is multiplied

by a factor between 0 and 2 subdivided into 64 steps.

With a contrast adjustment of 32 (gain=1) the signal

can be shifted by

±100 % of its maximal amplitude with

the digital brightness value. This is for adjustment of

the headrooms for under- and overshoot. After the

brightness addition, the negative going signals are lim-

ited to zero. It is desirable to keep a small positive off-

set with the signal to prevent undershoots produced by

the peaking from being cut.

Table 2–1: Scaler modes

Mode

Scale

Factor

Description

Panorama

4:3

→16:9

non-

linear

compr.

4:3 source displayed on

a16:9 tube,

borders distorted

Waterglass

16:9

→4:3

non-

linear

zoom

Letterbox source (PAL+)

displayed on a 4:3 tube,

vertical overscan,

borders distorted,

no cropping

→40.5 MHz

1.5

linear

sample rate conversion

from external to internal

pixel clock

→40 MHz

1.25

linear

sample rate conversion

from external to internal

pixel clock

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