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25

U15

VSS

-

GND

GND

U16

VSS

-

GND

GND

U17

VSS

-

GND

GND

U18

VSS

-

GND

GND

U19

VSS

-

GND

GND

U20

VSS

-

GND

GND

U31

VDD1.2

-

1.2V

POWER SUPPLY

U32

LSI_IDDT

I

3.3V

LSI Test

U33

THRMAVSS

-

GND

A/D

U34

THRMSTR1

I

3.3V

A/D

V01

NSDCLK

O

2.5V

SDRAM Clock

V02

VSS

-

GND

GND

V03

SDMD13

IO

2.5V

SDRAM Data 

V04

VDD1.2

-

1.2V

POWER SUPPLY

V15

VSS

-

GND

GND

V16

VSS

-

GND

GND

V17

VSS

-

GND

GND

V18

VSS

-

GND

GND

V19

VSS

-

GND

GND

V20

VSS

-

GND

GND

V31

VDD3.3

-

3.3V

POWER SUPPLY

V32

THRMSTR0

I

3.3V

A/D

V33

TONEAVSS

-

GND

D/A_GND

V34

THRMAVDD

-

3.3V

A/D_POWER

W01

SDMD14

IO

2.5V

SDRAM Data 

W02

SDMD12

IO

2.5V

SDRAM Data 

W03

SDLDM1

O

2.5V

SDRAM Data Mask For Lower Byte (DQ[15:8])

W04

SDLDQS1

IO

2.5V

SDRAM Date Strobe for Lower Byte (DQ[15:8])

W15

VSS

-

GND

GND

W16

VSS

-

GND

GND

W17

VSS

-

GND

GND

W18

VSS

-

GND

GND

W19

VSS

-

GND

GND

W20

VSS

-

GND

GND

W31

TONEAVDD

-

3.3V

D/A POWER SUPPLY

W32

DMACS1

IO

3.3V

PCCIO22

W33

DMACS0_NVIDEO

IO

3.3V

Video Data

W34

TONE

O

3.3V

D /A

Y01

VDD2.5

-

2.5V

POWER SUPPLY

Y02

SDMD11

IO

2.5V

SDRAM Data 

Y03

SDMD8

IO

2.5V

SDRAM Data 

Y04

VSS

-

GND

GND

Y15

VSS

-

GND

GND

Y16

VSS

-

GND

GND

Y17

VSS

-

GND

GND

Y18

VSS

-

GND

GND

Y19

VSS

-

GND

GND

Y20

VSS

-

GND

GND

Y31

VSS

-

GND

GND

Y32

DMAACK_CPMSERCK

IO

3.3V

PCCIO19 

Y33

DMACLK_PWRDWN

IO

3.3V

PCCIO20

Y34

DMAINT

IO

3.3V

PCCIO23

PIN NO.

PinName

I/O

POWER SUPPLY 

VOLTAGE

EXPLANATION

26

1. Function

This unit has a lithium battery (BAT300) which works for the Real Time Clock IC (RTC: inside IC300).
The RTC continues to work, backed up by a lithium battery even when the power switch is OFF.

2. RTC Inside (IC300) Backup Circuit Operation

When the power switch is turned ON, power is supplied to the RTC (inside IC300). At this time, the voltage at pin B22 of the
IC300 is +3.3V. When the power switch is turned OFF, the BAT300 supplies power to RTC through DA300. 
When the power switch is OFF and the voltage of +3.3V decreases, pin B22 of RTC (IC300) becomes roughly the same volt-
age as the battery voltage. RTC goes into the backup mode, in which the power consumption is lower.

27

The modem (Included IC300) has all the hardware satisfying the CCITT standards mentioned previously.
ALL processing is controlled by the SOC (IC300) according to CCITT procedures.
This modem (Included IC300) has an automatic application equalizer. With training signal 1 or 2 at the time of G3 reception, it can
automatically establish the optimum equalizer.  

The digital image data sent on ATXD line from modem (Included IC300) .
DAA IC100(6

→9,10), Lineside DAA IC101 and the NCU section to the telephone line.

The analog image data which is received from the telephone line passes through the NCU section and enters lineside DAA*

IC100. The signals are changed to digital data in IC100 (5,6) ,IC101(9,10

→5) and IC300. In this case, the image signals from

the telephone line are transmitted serially. 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 con-
stant receiving sensitivity.

The path is the same as Facsimile Reception.

This is the call signal which is generated the SOC (IC300) and sent to the speaker.

 DAA : Direct Access Arrangement

28

Composed of ITS circuit and NCU circuit.

The analog section works as an interface between the telephone line.
DAA control ITS circuit and NCU circuit. 
DAA control signals are output from Soc IC300.

[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; Remote fax activation circuit.
Refer to NCU Section (P.29) for the details.