ADE3050SX View Datasheet(PDF) - STMicroelectronics

Part Name

Description

Manufacturer

ADE3050SX

LCD Display Engines with Integrated DVI, ADC and YUV Ports

STMicroelectronics 

ADE3XXX

OSD Block

q Graphics character attributes: per-pixel color, vertical/horizontal mirroring

q Row attributes: double width, double height

q Window attributes: window visibility, position, size, border shadow, color table

q Global attributes: OSD visibility, OSD screen position, alpha fade in/fade out, global size

doubling, rotation in ninety-degree increments

q Single-bit enable/disable

For information on OSD programming, see the OSD Programming Manual.

OSD Access via I2C

The OSD uses a dedicated memory space accessible through an I2C port. The data stream sent to

the OSD register starts with two header bytes. These specify the type of transfer and the row/

column position for screen map transfers, the character index for font definition transfers, or the

color index for color map transfers.

A stream of OSD writes to the OSD I2C register can fill in a segment of the OSD memory space with

an internal auto-incrementing index register. The protocol is as follows:

1. Issue a start sequence with the R/W bit set to W.

2. Write to the OSD register. The first byte transferred is the index of the first internal OSD

register to be written. The next byte contains the data to be written to that register. Subsequent

bytes are written to successive internal OSD registers.

3. Continue writing data bytes until the desired range of OSD internal registers has been written

(the ADE3XXX device will issue an ACK on each transfer).

4. Issue an I2C stop sequence.

Character Display

There are two 96-character monochrome fonts and two 32-character four-bit color fonts, a total of

256 characters. The four bits of color are an index into one of two 16 entry color look-up tables.

Entries in the color look-up table specify a 24-bit RGB color. All fonts and the color look-up table are

RAM-based and must be downloaded to the OSD’s internal RAM before use. Font addressing is as

follows: character indexes 0x00-0x1F refer to color font 0, 0x20-0x7F refer to monochrome font 0,

0x80-0x9F refer to color font 1 and 0xA0-0xFF refer to monochrome font 1.

Screen Map

The OSD uses a character map of 15 rows x 30 columns. Each character occupies one byte. The

value of each byte indicates the character to display.

The OSD character map is addressed by specifying the row and column as part of the data transfer.

Attribute Map

The attribute map is defined as 16 rows by 31 columns. It has an extra row and an extra column

compared to the screen map.

The values corresponding to printable row/column addresses provide character attributes. Each

character on the screen has an attribute byte specifying (in the case of monochrome fonts) three

bits of background color, four bits of foreground color, and a blink on/off bit.

Blinking, when enabled, has a period of 100 frames (50 frames on, 50 frames off).

Column 31 of each row contains row attributes. These include the fourth bit of the background color

and two bits controlling double-height and double-width text.

Row 15 contains global attributes, including vertical and horizontal OSD position on the screen,

alpha blending, shadow/bordering, OSD rotation, color map selection, and normal/double size.

Alpha blending allows the OSD display to be mixed with the incoming video signal for transparency

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