Yamaha Aventage RX-A770, Service Manual

Page: 91 / 207

91
RX-V683/RX-A770
RX-V683/RX-A770
• Microprocessor extended port
IC76, 78: SN7 4 LV 4 0 5 1APWR (DIGITAL (1) P.C.B.)
8-channel analog multiplexers/demultiplexers
IC76
Pin
No.
Port Name Function Name
I/O
Detail of Function
Related Power Supply
OFF ON
1 Y4 PS1_PRT +3.3S_PON I I Power Supply protection 1
2 Y6 PS2_PRT +3.3S_PON I I Power Supply protection 2
4 Y7 AUD_DET PRY I I Audio signal detection
5 Y5 THM3 PRY I I Temperature detection 3
12 Y3 – +3.3S_PON I I No used
13 Y0 HWDET +3.3S_PON I I Hardware detection
14 Y1 TEST2 +3.3S_PON I I Model distinction
15 Y2 PS3_PRT AC I I Power Supply protection 3
IC78
Pin
No.
Port Name Function Name
I/O
Detail of Function
Related Power Supply
OFF ON
1 Y4 THM1 +3.3S_PON I I Temperature detection 1
2 Y6 THM2 +3.3S_PON I I Temperature detection 2
4 Y7 AMP_OLV PRY I I Amplifier output level detection
5 Y5 DC_PRT PRY I I DC protection
12 Y3 THM4 +3.3S_PON I I Temperature detection 4 (No used)
13 Y0 USB_VBUS_PRT +3.3S_PON I I Front USB overcurrent detection
14 Y1 TEST1 +3.3S_PON I I Destination distinction
15 Y2 TEST3 +3.3S_PON I I Special mode distinction
Y0
Y1
Y2
Y3
Y4
Y5
Y6
Y7
COM
INH
C
B
A
11
10
9
6
3
13
14
15
12
1
5
2
4
1
2
3
4
5
6
7
8
9
10
16
15
14
13
12
11 Y4
Y6
COM
Y7
Y5
INH
GND
GND
V
CC
Y2
Y1
Y0
Y3
A
B
C
INPUTS
ON
CHANNEL
INH
L
L
L
L
L
L
L
L
H
L
L
L
H
H
H
H
X
C
L
L
H
H
L
L
H
H
X
L
H
L
H
L
H
L
H
X
L
Y1
Y2
Y3
Y4
Y5
Y6
Y7
None
Y0
B A