LC74794 データシートの表示（PDF） - SANYO -> Panasonic

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LC74794

On-Screen Display Controller LSI

SANYO -> Panasonic 

Pin Assignment

LC74794, 74794M

Pin Functions

Pin no.

1

2

3

Pin

VSS1

XtalIN

XtalOUT

(MUTE)

Ground

Function

Crystal oscillator

(MUTE input)

CTRL1 Crystal oscillator input switching

4 (CHABLK) (CHABLK output)

5

CS2 Enable input 2

6

SCLK2 Clock input 2

7

DOUT Data output

External synchronizing signal judgment

8 SYNCJDG output

Notes

Ground connection (digital system ground)

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

oscillator to generate 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 the MUTE pin is set low, the video output is held at the pedestal level. (A pull-up

resistor is built in so the input has hysteresis characteristics.)

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.

PDC/VPS data output enable input. Data output is enabled by a low-level input. (A pull-up

resistor is built in so the input has hysteresis characteristics.)

Clock input for PDC/VPS data output

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

PDC/VPS data output

(This is either an n-channel open-drain output or a CMOS output.)

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

Outputs a high level when synchronizing signals are present.

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

output on command resets.)

Continued on next page.

No. 5557-2/30

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