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参数资料
| 型号： | LM1247AAG/NA/NOPB |
| 厂商： | NATIONAL SEMICONDUCTOR CORP |
| 元件分类： | 音频／视频放大 |
| 英文描述： | 3 CHANNEL, VIDEO PREAMPLIFIER, PDIP24 |
| 封装： | PLASTIC, DIP-24 |
| 文件页数： | 11/48页 |
| 文件大小： | 3141K |
| 代理商： | LM1247AAG/NA/NOPB |
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OSD Generator Operation (Continued)
ATTRIBUTE TABLES
Each character has an attribute value assigned to it in the
page RAM. The attribute value is 4 bits wide, making each
character entry in the page RAM 12 bits wide in total. The
attribute value acts as an address which points to one of 16
entries in either the two-color attribute table RAM or the
four-color attribute table RAM. The attribute word in the table
contains the coding information which defines which color is
represented by color 0 and color 1 in the two color attribute
table and color 0, color 1, color 2, color 3 in the four-color
attribute table. Each color is defined by a 9-bit value, with 3
bits assigned to each channel of RGB. A dynamic look-up
table defines each of the 16 different color “palettes”. As the
look-up table can be dynamically coded by the microcontrol-
ler over the I
2C compatible interface, each color can be
assigned to any one of 2
9 (i.e. 512) choices. This allows a
maximum of 64 different colors to be used within one page
using the 4-color characters, with up to 4 different colors
within any one character and 32 different colors using the
2-color characters, with 2 different colors within any one
character.
TRANSPARENT DISABLE
In addition to the 9 lines of video data, a tenth data line is
generated by the transparent disable bit. When this line is
activated, the black color code will be translated as “trans-
parent” or invisible. This allows the video information from
the PC system to be visible on the screen when this is
present. Note that this feature is enabled on any black color
in of the first 8 attribute table entries.
ENHANCED FEATURES
In addition to the wide selection of colors for each character,
additional character features can be selected on a character
by character basis. There are 3 Enhanced Feature Regis-
ters, EF0, EF1 and EF2.
1.
Button Boxes — The OSD generator examines the char-
acter string being displayed and if the “button box” at-
tributes have been set in the Enhanced feature byte,
then a box creator selectively substitutes the character
pixels in either or both the top and left most pixel line or
column with a button box pixel. The shade of the button
box pixel depends upon whether a “depressed” or
“raised” box is required, and can be programmed
through the I
2C compatible interface. The raised pixel
color (“highlight”) is defined by the value in the color
palette register, EF1 (0x8405 - 0x8406), which is nor-
mally set to white. The depressed pixel (“lowlight”) color
by the value in the color palette register, EF2 (0x8407 -
0x8408), which is normally set to gray. See Figure 19 for
detail and Figure 20 for the on-screen effect.
2.
Heavy Button Boxes — When heavy button boxes are
selected, the color palette value stored in register EF3
(0x8409 - 0x840A) is used for the depressed (“lowlight”)
pixel color instead of the value in register EF2.
3.
Shadowing — Shadowing can be added to two-color
characters by choosing the appropriate attribute value
for the character. When a character is shadowed, a
shadow pixel is added to the lower right edges of the
color 1 image, as shown in Figure 21. The color of the
shadow is determined by the value in the color palette
register EF3, which is normally set to black.
4.
Bordering — A border can be added to the two-color
characters. When a character is bordered, a border pixel
is added at every horizontal, vertical or diagonal transi-
tion between color 0 and color 1. See Figure 22. The
color of the border is determined by the value in the color
palette register EF3 (normally black).
5.
Blinking — If blinking is enabled as an attribute, all colors
within the character except the button box pixels which
have been overwritten will alternately switch to color 0
and then back to the correct color at a rate determined
by the microcontroller through the I
2C compatible
interface.
20048433
FIGURE 18. Displaying Each Character Individually
LM1247
www.national.com
19
相关PDF资料 |
PDF描述 |
|---|---|
| LM1253AAE/NA | ON-SCREEN DISPLAY IC, PDIP28 |
| LM1267NA/NOPB | 3 CHANNEL, VIDEO PREAMPLIFIER, PDIP24 |
| LM1269NA/NOPB | 3 CHANNEL, VIDEO PREAMPLIFIER, PDIP24 |
| LM1276AAA/NA | 1 CHANNEL, VIDEO PREAMPLIFIER, PDIP28 |
| LM1279AN/NOPB | 3 CHANNEL, VIDEO AMPLIFIER, PDIP20 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LM1247DMC/NA | 制造商:Texas Instruments 功能描述: |
| LM124A | 制造商:NSC 制造商全称:National Semiconductor 功能描述:Low Power Quad Operational Amplifiers |
| LM124AD | 制造商:STMICROELECTRONICS 制造商全称:STMicroelectronics 功能描述:LOW POWER QUAD OPERATIONAL AMPLIFIERS |
| LM124ADR | 制造商:TI 制造商全称:Texas Instruments 功能描述:QUADRUPLE OPERATIONAL AMPLIFIERS |
| LM124ADT | 制造商:未知厂家 制造商全称:未知厂家 功能描述:Voltage-Feedback Operational Amplifier |
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