AL250/251 Data Sheets
AL250
July 28, 1999
2
Contents
1.0 Features ___________________________________________________________________ 3
2.0 Applications ________________________________________________________________ 3
3.0 General Description__________________________________________________________ 4
4.0 Pinout Diagrams ____________________________________________________________ 5
5.0 Pin Definition and Description _________________________________________________ 6
6.0 Functional Description _______________________________________________________ 8
6.1 Digital Input/Output Data Formats _________________________________________________ 8
6.2 Default Resolution _______________________________________________________________ 9
6.3 Video Timing____________________________________________________________________ 9
6.4 Border/Border Color ____________________________________________________________ 13
6.5 OSD Interface __________________________________________________________________ 14
6.6 External Overlay________________________________________________________________ 15
6.7 Look-up Table (LUT) ____________________________________________________________ 16
6.8 I
2
C Programming _______________________________________________________________ 16
6.9 Video Decoding _________________________________________________________________ 18
7.0 Electrical Characteristics ____________________________________________________ 20
7.1 Recommended Operating Conditions_______________________________________________ 20
7.2 Characteristics _________________________________________________________________ 20
8.0 AL250/251 Register Definition ________________________________________________ 22
8.1 Register Description _____________________________________________________________ 23
9.0 Board Design and Layout Considerations _______________________________________ 29
9.1 Grounding _____________________________________________________________________ 29
9.2 Power Planes and Power Supply Decoupling ________________________________________ 29
AL250
July 28, 1999
3
AL250/251
Video Scan Doubler
1.0 Features
Convert interlaced TV signal (NTSC/PAL)
into non-interlaced RGB format for CRT
monitors or LCD panels
Highly integrated design with built-in DAC,
SRAM, OSD and LUT
Built-in on-screen-display with programmable
bitmap
Interpolated scan doubling with no tearing or
jagged edge artifacts
Reduced interlace flicker
Auto NTSC/PAL detect
Digital video input of square pixel, ITU-RBT
601 (CCIR 601), or user-defined format
Analog/digital non-interlaced RGB (VGA)
signal output (Scan Doubled or Deinterlaced)
I
2
C programming interface
Power-down control via I
2
C
Internal RGB video lookup table (LUT) to
provide gamma correction and special effects
Overlay support for title making and complex
on-screen display
Self-initialization without software (Plug &
Play)
3.3 or 5 volt support
16-bit digital RGB/YUV output (AL251 only)
2.0 Applications
TV-ready Multimedia Computer Monitor
TV to PC Video Scan Converter Box
Progressive Scan TV
Video Game Station
DVD Player
LCD TV Monitor
8-bit DAC
8-bit DAC
8-bit DAC
Video Processor
and Scan Doubler
R
G
B
Timing
Control
I
2
C Circuit
VCLK
HREF
SCL
SDA
I
2
CADDR
AL250-01
Digital
YUV or RGB
input
Mode Control
Video
Formatter
RGB
Video
Lookup
Tables
Video Memory
GHREF
GVS
GHS
OVLCTRL
STD
INTYPE
SQUARE
VIDHS
VIDVS
RSET
VREF
COMP
RESET
VCLKX2
On-screen
Display
16
16
Digital YUV or
RGB output
(AL251)
2
AL250
July 28, 1999
4
3.0 General Description
The AL250/251 Video Scan Doubler (De-Interlacer) is a video conversion chip for consumer video
and multimedia applications. It converts interlaced NTSC or PAL, ITU-RBT 601 (CCIR 601) or
square pixel, YUV422 or RGB565 digital signals into computer monitor RGB signals for direct
connection to a computer monitor or progressive scan TV.
By using I
2
C interface control, the AL250/251 can also be programmed to co-ordinate with various
input resolutions, adjust screen positioning and crop video noise from around the original input video
boundary.
The internal RGB video lookup tables (LUT), which are controlled via I
2
C interface, can provide
gamma correction for calibrating the color accuracy of different types of CRT's and improving the
contrast level to display more vivid pictures.
A built-in on-screen-display (OSD) provides programmable bitmap RAM for custom design icons
and on-screen control panels.
Overlay function is supported to create titling or on-screen-display menus for video adjustment.
The AL251 provides all the features of the AL250. Additionally, it has digital output in YUV422 or
RGB565 format
, and can convert NTSC video for VGA LCD panels
.
The AverLogic proprietary digital signal processing technology creates a highly stable video image
without tearing effects or jagged edges. The output picture is smoother and has less flicker than the
original input signal/picture.
AL250
July 28, 1999
5
4.0 Pinout Diagrams
HREF
9
STD0
10
STD1
11
GND
12
INTYPE
13
SQUARE
14
TESTIN
15
I2CADDR
16
/RESET
17
SDA
18
VDD
19
SCL
20
VDD
21
DO8
22
DO9
23
24
NC
1
NC
2
VIDHS
3
VDD
4
VCLK
5
VIDVS
6
GND
7
VCLKX2
8
D011
GREF
26
25
GVS
GHS
28
27
AGND
AB
30
29
AVDD
AG
32
31
AGND
AR
34
33
AVDD
RSET
36
35
COMP
VREF
38
37
NC
40
39
DO7
DO6
VDD
VDD
DO5
DO4
DO3
DO2
DO1
DO0
OVLCTRL1
OVLCTRL0
GND
NC
NC
NC
DO13
DO12
VDIN4
VDIN3
VDIN2
VDIN1
VDIN0
GND
56
55
54
53
52
51
50
49
48
47
46
45
44
43
42
41
64
63
62
61
60
59
58
57
NC
VDIN15
VDIN14
VDIN13
VDIN12
GND
VDIN11
VDIN10
VDIN9
VDD
VDIN8
VDIN7
VDIN6
VDIN5
DO15
DO14
79
80
77
78
75
76
73
74
71
72
69
70
67
68
65
66
AL251-01 pinout diagram
AL251
NC
D010
AL250
VIDHS
1
VDIN5
52
VDD
2
VDIN4
51
VCLK
3
VDIN6
53
VIDVS
4
VREF
32
GND
5
VDIN7
54
VCLKX2
6
VDIN3
50
HREF
7
VDIN8
55
STD0
8
COMP
31
STD1
9
VDD
56
GND
10
VDIN2
49
INTYPE
11
VDIN9
57
SQUARE
12
TESTIN
13
VDIN10
58
I2CADDR
14
VDIN1
48
/RESET
15
VDIN11
59
SDA
16
RSET
30
VDD
17
GND
60
SCL
18
VDIN0
47
VDD
19
VDIN12
61
AVDD
29
VDIN13
62
GND
46
VDIN14
63
VDIN15
64
TESTY7
45
AR
28
TESTY6
44
AGND
27
VDD
43
VDD
42
AG
26
TESTY5
41
AVDD
25
TESTY4
40
TESTY3
39
AB
24
TESTY2
38
AGND
23
TESTY1
37
TESTY0
36
GHS
22
OVLCTRL1
35
GVS
21
OVLCTRL0
34
GND
33
GREF
20
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