2. LCD image processing circuit
LCD image processing circuit is composed of MST7187 And peripheral elements, Responsible for
switching the exterior inputted analog video signals into signals required by LCD drive.
MST518 is a high-performance and high integration picture processing chip designed for LCD,
which can support SXGA format. multi-format output display jack (support TTL, LVDS, RSDS). This
player adopts analog signal, MST718 built-in MCU, MST518VA has multi-format output display jack. TTL
output means is adopted in this player and the output means can be adjusted through software
according to screen’s drive means.MST7187outputs DR0~DR7/DG0~DG7/DB0~DB7 to drive display
screen, and also outputs clock, enable and synchronous signals to supply for the working of screen (770
OCLK clock output, 78 DE enable signal, 79 VSYNC filed synchronous output and 80 HSYNC line
synchronous output).
3.2.4 Input circuit
External input means of TV has SCART\CVBS and Y/PB/PR, and also composite video and stereo
audio output function.
1.Introduction to SCART terminal :
SCART terminal is a standard input port in Europe. In this jack circuit, many dual-direction diodes
are adopted and act as protection function to prevent the instability of externally-conected device or
damage of the machine due to static. SCART pin function is shown in the following table:
Pin
Name
Signal
direction
Function description
Pin
Name
Signal
direction
Function description
1
A(B)OUT
I
Audio right channel input
12
NC
Network communication data line 2
2
A(B)IN
O
Audio right channel output
13
RETURN
Pr signal ground
3
A(A)OUT
I
Audio left channel input
14
RETURN
Blanking signal ground
4
A-COM
Audio signal ground
15
RED I/O
I/O
Pr signalI/O port
5
RETURN
Pb signal ground
16
BLK I/O
I/O
Blanking signal I/O port
6
A(A)IN
O
Audio left channel output
17
RETURN
Blanking signal ground
7
BLUE I/O
I/O
Pb signalI/O port
18
TRTURN
Composite video signal ground
8
FUNCSW
I
Function selection jack
19
V-OUT
I
Composite video signal input
9
RETURN
Y1 signal ground
20
V-IN
O
Composite video signal output
10
CONT
I/O
Network communication data
line 2
21
GND
Common
11
GREEN I/O
I/O
Y1 signal I/O port
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