LC74785M Просмотр технического описания (PDF) - SANYO -> Panasonic

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Компоненты Описание

производитель

LC74785M

On-Screen Display Controller LSI

SANYO -> Panasonic 

Pin Assignment

LC74785, LC74785M

Pin Functions

Pin No.

1

2

Pin

VSS1

Xtal IN

3

Xtal OUT

(MUTE)

Function

Ground

Crystal oscillator

(MUTE input)

Notes

Ground connection (digital system ground)

These pins are used either to connect the crystal and capacitor used to form an

external crystal oscillator used to generate the internal synchronizing signals, or

to input an external clock signal (2fsc or 4fsc). As a mask option, the Xtalout pin

can be set to function as the MUTE input pin. When this pin is set low, the video

output is held at the pedestal level. (A pull-up resistor is built in and the input has

hysteresis characteristics.)

CTRL1

4

(CHABLK)

Crystal oscillator input switching

(CHABLK output)

Switches the mode between external clock input and crystal oscillator operation.

A low level selects crystal oscillator operation and a high level selects external

clock input. As a mask option, the CTRL1 input pin can be set to function as the

CHABLK (character border) output. This is a 3-value output.

5

LN21

Data output

Line 21H pulse output

(Even fields when MOD1 is low, both fields when MOD1 is high)

6

OSC IN

7

OSC OUT

LC oscillator

Connections for the coil and capacitor that form the character output dot clock

generation oscillator.

Outputs the state of the external synchronizing signal presence/absence judgment. Outputs a

high level when synchronizing signals are present.

Outputs a field discrimination pulse (O/E pulse) when SEL2 is high.(HLFTON: Valid when 0)

HLFTON: A signal in the range specified by LNA*, LNB*, and LNC* is output when HLFTON is

8

SYNC JDG

External synchronizing signal judgment output high.)

Outputs the dot clock (LC oscillator) when CS1 is high and RST is low. (This signal is not

output on command resets.)

Outputs the crystal oscillator clock when CS1 is low and RST is low. (This signal is not output

on command resets.)

9

CS1

10

SCLK

11

SIN

12

VDD2

13

CVOUT

14

VSS2

Enable input

Clock input

Data input

Power supply

Video signal output

Ground

Enable input pin for the OSD serial data input function.

Serial data input is enabled when this pin is low.

A pull-up resistor is built in. (The input has hysteresis characteristics.)

Input for the serial data input clock.

A pull-up resistor is built in. (The input has hysteresis characteristics.)

Serial data input. A pull-up resistor is built in. (The input has hysteresis

characteristics.)

Composite video signal level adjustment power supply (analog system power

supply)

Composite video signal output

Ground connection (analog system ground)

Continued on next page.

No. 5520-2/24

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