CS7666 View Datasheet(PDF) - Cirrus Logic

Part Name

Description

Manufacturer

CS7666

Digital Color-Space Processor for CCD Cameras

Cirrus Logic 

CS7666

mon target resolutions for the scaler are 640 and

720 pixels per line (square and rectangular pixel

formats), but it is possible to provide generic scal-

ing of M/N where M and N are values from 1 to 31.

The CS7615 and CS7666 chip set supports a wide

range of imager formats while providing an output

format that follows the ITU-601 Component Digi-

tal Video recommendation. The ITU-601 docu-

ment primarily specifies horizontal resolutions of

720 active horizontal pixels (which is required for

broadcast television compatibility). However,

many of today’s digital video receivers are capable

of operating with a wide range of video image for-

mats. Even though these digital video receivers al-

low image formats not specified in the ITU-

601/656 recommendation, all of these receivers ex-

pect the basic ITU-601/656 protocol to be followed

in terms of data sequence and timing cues. This is

the case with the CS7666, where all output formats

follow the ITU-601/656 recommendation even if

the image formats differ in horizontal and vertical

pixel dimensions.

The 640 Pixel Horizontal Line

The following discussion assumes that a 512 hori-

zontal pixel class imager has been selected for the

camera, the CS7615 has been programmed to pro-

vide 512 active pixels and 112 inactive pixels, and

that the internal 4:5 horizontal scaler has been en-

abled (scaler mode 1). Many other imager/scaler

combinations are possible, but the digital video for-

mat would not be significantly different than the

640x480 case described.

Transmitted during each active line are 1280 mul-

tiplexed luminance and chrominance values (640

luminance, 320 chrominance Cr, and 320 chromi-

nance Cb values). Eight of the remaining 280 inter-

face clock intervals are used to transmit

synchronizing information. The first of these 1560

interface clock intervals is designated line 0 word 0

for the purpose of reference only. The 1560 sample

words per total line are therefore numbered 0

through 1559. Intervals 0 through 1279, inclusive,

contain video data.

The interface clock intervals occurring during dig-

ital blanking are designated 1280 through 1559. In-

tervals 1280 through 1283 are reserved for the end-

active-video (EAV) timing reference. Intervals

1556 through 1559 are reserved for the start-of-ac-

tive-video (SAV) timing reference. Figure 3 indi-

cates the values of the timing reference signals (F,

V, H) for an entire frame of interlaced video. Please

note the scan lines are numbered 1 through 525

consecutively in the time domain (spatially they are

interlaced). Table 1 defines the 1560 samples of a

single scan line of video.

DS302PP1

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