FUNCTIONAL DESCRIPTION

The STV5730 operates in ”mixed mode” or ”full

page mode” :

- Mixed mode : the device is line locked to the

incoming CVBS signal. The text is superimposed

over the CVBS input either in B&W or translucent.

It may also be superimposed in color by using the

R/G/B outputs.

- Full page mode : the device generates a colored

PAL or NTSC CVBS output and simultaneous

R/G/B outputs.Both ”normal full page” and ”video

full page” modes are supported by the STV5730.

In the ”normal full page ” the screen background

is uniformely colored, while the ”video full page”

mode permits to display the unlocked VIDEO IN

signal in the screen background area.

It performs the following text features :

- Page composition : 11 rows X 28 characters

- Number of displayed characters : 308 (max)

- Character composition : 12 dots X 18 lines

- ROM character set : 128 user definable characters

- Screen display positions : 58 horizontal positions,

63 vertical positions

- Row position offset , each row : Xoffset from 0 to

+15, Yoffset from -17 to +17

- Display enable : each row or page

- Character color : 1 out of 8, each character

- Character background color : 1 out of 8, character

and page enabled or set identical to character

color

- Character border color : 1 out of 8, row enabled

or set identical to character color

- Page background color : 1 out of 8

- Zoom : 3 independant zoom factors for rows 0,

1 to 9 and 10.

- Zoom factors : four independant X and Y zoom

factors

- Blink : character and page enabled

- Blink frequency : 0.5 or 1.0 second

- Blink duty cycle : 0.25, 0.5 or 0.75

1 - THE INTERNAL RAM BUFFER

It stores the page (i.e. the text definition) and the row attributes.

1.1 - Page

The page includes 11 row buffers, numbered from 0 to 10. Each row buffer includes 28 characters,

numbered from 0 to 27. The characters may be written one by one by the microprocessor for random access.

They also may be written sequentially, starting with any character address.

1.2 - Character Format and Attributes

11

10

9

8

7

6

0

BE

R

G

B

BK

CHARACTER CODE

CHARACTER CODE : 1 character out of 128 from the character ROM

BK

: BK=0 : character blink disabled

BK=1 : character blink enabled

R/G/B

: Character color :

000

001

010

011

100

101

110

111

black

blue

green

cyan

red

magenta

yellow

white

BE

: BE=0 :

BE=1 :

the character background is disabled

the character background is enabled

STV5730

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