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KX-T7436C/KX-T7436C-B
4. DATA COMMUNICATION CIRCUIT
1) Function
The data communication circuit serves the following functions:
Information exchanger between the DSHS and DSHS proprietary telephone, key input information as well as data for
the LED control, LCD control, etc. This information is continuously exchanged at all times.
2) Circuit Operation
When the DSHS proprietary telephone receives an IRQ signal from the DSHS and after sending the key input
information to the DSHS and receiving data for the LED control, etc., the DSHS proprietary telephone will return to the
DSHS an acknowledge signal.
3) Reception
The data from the DSHS is received via the H and L lines along the path shown below.
H, L Line
→
T1
→
IC11 Pin 5, 10
→
IC1 Pin 38, 39
→
IC1 Pin 21
→
IC2 Pin 22
(IC5 Pin 8)
4) Transmission
The data to the DSHS proprietary telephone is transmitted along the following path.
IC2 Pin 23
→
IC1 Pin 20
→
IC1 Pin 40, 41
→
Q1, Q2
→
T1
→
H, L Line
(IC5 Pin 13) (IC1 Pin 19)
Circuit Diagram
IC2
COMMUNICATION LSI
IC5
CODEC FOR OHCA
RXD
TO HANDSET
SP-PHONE
SP-PHONE
TXD
-FSYNC
BCLK
22
21
23
20
24
25
15
SXO
SR1
EP2
18
CK2M
19
SRO
16
EP3
IC1
Transmission
To PBX
XDP PORT
Reception
TXA
TXB
RXA
RXB
40
41
38
39
C5
C7
R8
R11
R2
R3
C6
R6
+5V(V1)
R1
Q1
Q2
7
9
10
+
–
8
VREF
C80
+ –
+
–
C3
R4
+5V(V1)
R7
R10
R9
C8
+5V(V1)
4
5
R13
R12
C9
+
–
–
12
R5
4
10
T1
L1
4 H
JK1
L4
D1
1
7
2
6
C2
+
–
~
~
L2
+5V(V1)
OUT
IN
IC9
C11
OUT
IN
GND
C10
C106
+
–
+
–
5
9
IC11
IC11
3
C1
( )
C4
DR
TO OHCA
SP-PHONE
SP-PHONE
DT
MCLK
FST, R
8
13
11, 9, 12
14, 7
1 L
3 T
2 R
3 T
2 R
1 G
CN5
JP1
2 R
3 B
4 W
3 B
4 W
+5V(V2)
IC10
C13
C12
C107
+
–
+
–
JP2
JP3
JP4
JP3
JP4
JP8
JP7
JP6
JP5
JP16
3 1
2
GND
3 1
2
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