Marantz SR7500/A1B Service Manual page 63

IC23 (DSP PCB) : CS4382
IC78 (VIDEO PCB) : LC74781
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IC78 (VIDEO PCB) : LC74781
Pin Functions
Pin No. Symbol Function
1 V 1 Ground Ground connection (digital system ground)
SS
2 Xtal
Used to connect the crystal oscillator and capacitor used to generate the internal
IN
Crystal oscillator connection
synchronization signal, or to input an external clock (2fsc or 4fsc).
3 Xtal
OUT
Switches between external clock input mode and crystal oscillator mode.
4 CTRL1 Crystal oscillator input switching
Low = crystal oscillator mode, high = external clock mode
Outputs the blank signal (the OR of the character and border signals). (Outputs a composite
5 BLANK Blanking output sync signal when MOD0 is high.) Outputs the crystal oscillator clock during reset (when the
RST pin is low), but can be set up to not output this signal by microprocessor command.
6 OSC
Connections for the coil and capacitor that form the oscillator that generates the character
IN
LC oscillator connection
output dot clock.
7 OSC
OUT
Outputs the character signal. (Functions as the external synchronization signal discrimination
signal output pin when MOD0 is high, and outputs the state of the judgment as to whether the
8 CHARA Character output external synchronization signal is present or not. Outputs a high level when the synchronization
signal is present.) Outputs the dot clock (LC oscillator) during reset, but can be set up to not
output this signal by microprocessor command.
Serial data input enable input. Serial data input is enabled when low. A pull-up resistor is built in
9 CS Enable input
(hysteresis input).
Serial data input clock input.
10 SCLK Clock input
A pull-up resistor is built in (hysteresis input).
11 SIN Data input Serial data input. A pull-up resistor is built in (hysteresis input).
12 V 2 Power supply Composite video signal level adjustment power supply pin (analog system power supply).
DD
13 CV Video signal output Composite video signal output
OUT
14 NC Must be either connected to ground or left open.
15 CV Video signal input Composite video signal input
IN
16 V 1 Power supply Power supply (+5 V: digital system power supply)
DD
Video signal input for the built-in sync separator circuit (Used for either horizontal
17 SYN Sync separator circuit input synchronization signal or composite sync signal input when the built-in sync separator circuit is
IN
not used.)
18 SEP Sync separator circuit bias voltage Built-in sync separator circuit bias voltage monitor pin
C
Built-in sync separator circuit composite sync signal output. (When MOD1 is high, outputs a high
19 SEP Composite sync signal output level during internal synchronization and a low level during external synchronization.) (Outputs
OUT
the SYN
Vertical synchronization Inputs a vertical synchronization signal created by integrating the SEP
20 SEP
IN
signal input integrator must be attached at the SEP
The setting indicated by this pin takes priority in switching between the NTSC, PAL, PAL-M and
21 CTRL2 NTSC/PAL-M switching input PAL-N formats. A low level selects NTSC after a reset. The microprocessor command NTSC,
PAL, PAL-M, or PAL-N setting is valid. High = PAL-M format.
Controls whether or not the VSYNC signal is input to the SEP
22 CTRL3 SEP input control
IN
high = VSYNC not input.
23 RST Reset input System reset input. A pull-up resistor is built in (hysteresis input).
24 V 1 Power supply (+5 V) Power supply (+5 V: digital system power supply)
DD
Description
input signal when the internal sync separator circuit is not used.)
IN
pin output signal. An
OUT
pin. This pin must be tied to V
OUT DD
input. Low = VSYNC input,
IN
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1 if unused.