Panasonic KX-FLB803SA Service Manual ▷ View online
21
KX-FLB803SA
6.3.3.
MODEM CIRCUIT OPERATION
The modem (IC607) has all the hardware satisfying the CCITT standards mentioned previously.
When the SOC (IC600) is brought to a low level, the modem (IC607) is chip-selected and the resistors inside IC are selected by the
select signals from SOC (IC600) A[0]-A[5]. Commands are written through the data bus, and all processing is controlled by the SOC
(IC600) according to CCITT procedures. Here, the INT signal dispatched from IRQ (pin 1 of IC607) to the SOC (IC600) implements
post processing.
This modem (IC607) has an automatic application equalizer. With training signal 1 or 2 at the time of G3 reception, it can automati-
cally establish the optimum equalizer. The modem (IC607) operates using the 28.224MHz clock (X604).
Facsimile Transmission/DTMF Line Send
The digital image data on the data bus is modulated in the modem (IC607), and sent from pin 25, 26 via modem IC607, Analog gate
array IC209(24
When the SOC (IC600) is brought to a low level, the modem (IC607) is chip-selected and the resistors inside IC are selected by the
select signals from SOC (IC600) A[0]-A[5]. Commands are written through the data bus, and all processing is controlled by the SOC
(IC600) according to CCITT procedures. Here, the INT signal dispatched from IRQ (pin 1 of IC607) to the SOC (IC600) implements
post processing.
This modem (IC607) has an automatic application equalizer. With training signal 1 or 2 at the time of G3 reception, it can automati-
cally establish the optimum equalizer. The modem (IC607) operates using the 28.224MHz clock (X604).
Facsimile Transmission/DTMF Line Send
The digital image data on the data bus is modulated in the modem (IC607), and sent from pin 25, 26 via modem IC607, Analog gate
array IC209(24
→22), amplifier IC204(6→7) and the NCU section to the telephone line.
Refer to CHECK SHEET(P.158).
Facsimile Reception
The analog image data which is received from the telephone line passes through the NCU section and enters pin 29 of the modem
(IC607). The signals that enter pin 29 of the modem (IC607) are demodulated in the board to digital image signals, then placed on
the data bus.
In this case, the image signals from the telephone line are transmitted serially. Hence, they are placed on the bus in 8 bit units.
Here, the internal equalizer circuit reduces the image signals to a long-distance receiving level.
This is designed to correct the characteristics of the frequency band centered around 3 kHz and maintain a constant receiving sen-
sitivity.
It can be set in the service mode.
Refer to CHECK SHEET(P.158).
The analog image data which is received from the telephone line passes through the NCU section and enters pin 29 of the modem
(IC607). The signals that enter pin 29 of the modem (IC607) are demodulated in the board to digital image signals, then placed on
the data bus.
In this case, the image signals from the telephone line are transmitted serially. Hence, they are placed on the bus in 8 bit units.
Here, the internal equalizer circuit reduces the image signals to a long-distance receiving level.
This is designed to correct the characteristics of the frequency band centered around 3 kHz and maintain a constant receiving sen-
sitivity.
It can be set in the service mode.
Refer to CHECK SHEET(P.158).
Busy/Dial Tone Detection
The path is the same as FAX receiving. When it is detected, the carrier detect bit of the resistor in the modem (IC607) becomes 1,
and this status is monitored by SOC (IC600).
The path is the same as FAX receiving. When it is detected, the carrier detect bit of the resistor in the modem (IC607) becomes 1,
and this status is monitored by SOC (IC600).
Call Tone Transmission
This is the call signal which is generated the ASIC (IC604) and sent to the speaker.
This is the call signal which is generated the ASIC (IC604) and sent to the speaker.
22
KX-FLB803SA
6.3.4.
ANALOG SECTION
Composed of ITS circuit and NCU circuit.
6.3.4.1.
ANALOG GATE ARRAY (IC209)
The cross-point switch installed in this IC makes it possible to change the circuit configuration
for any analog signals such as the fax signals sent from the digital board. In addition,
this analog gate array integrates a handset circuit, input/output ports, etc.
This IC is controlled by SOC (IC600) through GATE ARRAY (IC604) on the digital board.
for any analog signals such as the fax signals sent from the digital board. In addition,
this analog gate array integrates a handset circuit, input/output ports, etc.
This IC is controlled by SOC (IC600) through GATE ARRAY (IC604) on the digital board.
Explanation of ANALOG GATE ARRAY (IC209 on the ANALOG Board)
No.
Name
Function
No.
Name
Function
1
STR
Strobe input
19
NC
Not used
2
CLOCK
Clock input
20
EXTIN
Ext amp output
3
DATA
Data input
21
EXTOUT
Ext amp input
4
VDD
Logic power supply
22
LINEOUT
Line amp output
5
VOXOUT
VOX output
23
LINEIN
Line amp input
6
VOXDET
VOX detection adjustment
24
MODEMTXIN
MODEM TX amp input
7
VOXIN
VOX input
25
MODEMTXOUT
MODEM TX amp output
8
VSS
Logic ground
26
NC
Not used
9
NC
Not used
27
TONEIN
Tone amp input
10
ROUT2
HS receiver amp output 2
28
NC
Not used
11
ROUT1
HS receiver amp output 1
29
NC
Not used
12
RIN
HS receiver amp input
30
GND
Analog ground
13
VCC
Analog ground
31
MODEMRXOUT
MODEM RX amp output
14
HSMICIN1
HS mic amp input 1
32
VLIN
Volume amp input
15
HSMICIN2
HS mic amp input 2
33
VREF
Reference voltage output
16
HSMICOUT
HS mic amp output
34
VLOUT
Volume amp output
17
NC
Not used
35
SPOUT
Speaker amp output
18
NC
Not used
36
SPIN
Speaker amp input
23
KX-FLB803SA
6.3.4.2.
DESCRIPTION OF BLOCK DIAGRAM IN ANALOG SECTION
Function
The analog section works as an interface between the telephone line.
The analog ASIC (IC209) on the analog board exchanges FAX TX and RX signals between the MODEM (IC607) and the analog
section.
The control signals transmitted to the analog section are output mainly from G/A IC604, and the analog status is stored as data
in G/A IC604.
The analog section works as an interface between the telephone line.
The analog ASIC (IC209) on the analog board exchanges FAX TX and RX signals between the MODEM (IC607) and the analog
section.
The control signals transmitted to the analog section are output mainly from G/A IC604, and the analog status is stored as data
in G/A IC604.
Circuit Operation
[NCU]: Network Control Unit the NCU comprises of the following; DC loop forming circuit to connect with the telephone line;
Switching circuit for other interconnected telephones; Bell detection circuit; Side tone circuit; Remote fax activation circuit.
Refer to NCU SECTION (P.31) for the details.
[NCU]: Network Control Unit the NCU comprises of the following; DC loop forming circuit to connect with the telephone line;
Switching circuit for other interconnected telephones; Bell detection circuit; Side tone circuit; Remote fax activation circuit.
Refer to NCU SECTION (P.31) for the details.
24
KX-FLB803SA
6.3.4.3.
BLOCK DIAGRAM
LINERLY
CIDRLY
Bell1
Break1
HSalc1
P-short1
DTMF Receiver
25
26
29
32
TXM
TXP
RX
HSMIC
INPUT
MLAT
MDATA
MCLK
ASIC SPOUT
HOOK
0/-6
A 5
A 4
A 3
A 2
A 1
D
0/-6
MUTE2
MUTE1
0/-1/-2/-3/-4/-5/6/7/8
0/-3
-20/-30
0/-6/-12
DET
20
EVOL0
EVOL2
EVOL1
TONE
VOX
Modem(Python)
TXM
TXP
RX
HSMIC
4
3
2
11
6
15
14
13
12
11
10
9
9
8
7
6
51
8
17
21
22
23
24
25
26
27
28
29
30
19
20
31
32
33
34
35
36
1
1
0
9
6
1
4
1
25
26
29
32
1
KX-FLB803SA: ANALOG BOARD:BLOCK
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