ViewSonic VP150M Service Manual - Page 29

Service

Manual

VP150m

ViewSonic

September

2000

-

Version

1.0

THEORY

OF

CIRCUIT

OPERATION

The

analog

input

RGB

signals

are

first

sampled

by

six

channels

of

the

8

-bit

A/D

converter,

and

the

48

-bit

RGB

data

is

then

fed

into

AM101-1.

For

digital

interface,

the

input

data

is

first

received

by

a

TMDS

receiver

and

the

24/48

bit

RGB

output

data

of

TMDS

receiver

is

then

fed

into

AM101-1.

Without

any

manual

adjustment,

AM101

is

capable

of

performing

automatic

detection

of

the

display

resolution

and

timing

of

input

signals

generated

from

various

PC

graphic

cards.

AM101-1

then

automatically

scales

the

input

image

to

fill

the

full

screen

of

the

LCD

display.

AM101-1

can

interface

with

TFT

LCD

panels

from

various

manufacturers

by

generating

either

24

-bit

or

48

-bit

RGB

signal

to

the

LCD

panel

based

upon

the

timing

parameters

saved

in

the

EEPROM.

The

AM101-1

implements

four

advanced

display

technologies:

1.

Advanced

mode

detection

and

auto

-calibration

without

any

external

CPU

assist

2.

Advanced

programmable

interpolation

algorithm

3.

Stand-alone

mode

support,

and

4.

Advanced

true

color

support

with

both

dithering

and

frame

modulation

The

AM101-1

also

provides

system

features specifically

intended

to

handle

the

TFT

LCD

display.

The

first

is

"plug

-and

-play",

and

the

second

is

"cost-effective

system solution".

To

be

truly

"plug

-and

-play",

the

AM101-1

performs

automatic

input

mode

detection

and

auto

phase

calibration,

so

the

LCD

display

can

ensure

that

the

A/D

converters'

sample

clock

is

precisely

synchronized

with

the input

video

data

and

preserves

the

highest

image

bandwidth

for

the

highest

image

quality.

Furthermore,

the

AM101-1

can

generate

output

video

even

when

the input

signal

is

beyond

the

specifications

or

no

input

signal

is

fed.

For

"cost-effective

system

solution",

the

AM101-1

implements

many

system

support

features

such

as

OSD

mixer,

error

status

indicators,

2

-wire

serial

interface

for

both

EEPROM

and

host

CPU

interface.

Another

important

contributing

factor

is

that

the

AM101-1

does

not

require

external

frame

buffer

memory

for

the

automatic

image.

Page

28

Confidential

—

Do

Not

Copy

ViewSonic VP150M Service Manual - Page 29

system solution.

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