Sony ICD-MS1 (serv.man2) Service Manual ▷ View online
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5
1-2. Microprocessor Interface
Fig. 1-2 shows the microprocessor interface of this unit.
1. Communication between System Controller IC722 and ADPCM CODEC IC164
The system controller IC722 controls the ADPCM IC164 by outputting the serial commands. These serial commands are output from pin-69 [TXD2] of the system controller
IC722 in synchronization with the clock of pin-70 [SCK2] of the system controller IC722. The selection of LP/SP and control of playback speed are performed by changing the
output frequency of pin-159 [SYNC] of the system controller IC722
The main interface is described as follows.
1. Communication between System Controller IC722 and ADPCM CODEC IC164
The system controller IC722 controls the ADPCM IC164 by outputting the serial commands. These serial commands are output from pin-69 [TXD2] of the system controller
IC722 in synchronization with the clock of pin-70 [SCK2] of the system controller IC722. The selection of LP/SP and control of playback speed are performed by changing the
output frequency of pin-159 [SYNC] of the system controller IC722
The main interface is described as follows.
Communication between system controller IC722 and ADPCM CODEC IC164 :
• Selection of the various modes (Record/Playback) of the signal processing block
• Selection of the recording modes (SP/LP) during recording
SP : 11 kHz, 3 bits/LP : 8 kHz, 2 bits
• Control of the speed control during playback, and others.
2. Communication between System Controller IC722 and LCD Module (LCD720)
The system controller IC722 outputs the data to be displayed on the LCD from pin-24 [LCD DO] while synchronizing it with the clock of pin-78 [LCD SCK]. Thus IC722 drives
the LCD module. The system controller IC722 has the signal input terminal of pin-25 [LCD DI] that is not used at present.
3. Communication between System Controller IC722 and REAL TIME CLOCK (Timer) IC721
The system controller IC722 outputs the data such as watch setup data from pin-69 [TXD2] to pin-7 [DATA] of the RTC (REAL TIME CLOCK) IC721 in synchronization with the
clock of pin-70 [SCK2] and the chip select signal of pin-17 [RTC CE]. At the startup of this unit, RTC IC721 outputs the watch information that is based on the received data, to
pin-68 [RXD2] of the system controller IC722 in synchronization with the clock of pin-70 [SCK2] and the chip select signal of pin-17 [RTC CE] of the system controller IC722. By
this communication, the system controller IC722 obtains the watch information. RTC IC721 also outputs the timer interrupt output such as alarm, and others to pin-149
[RTCINT1] and pin-148 [RTCINTR] of the system controller IC722 from pin-4 [/AIRQ] and pin-5 [/TIRQ] of the RTC IC721. This output is connected to the wake-up detection
circuit that starts up the unit at the timer's preset time. When the unit starts up by the timer, the corresponding audio data, priority, title, alarm information and other data that
have already been saved in the Memory Stick, are read out from the Memory Stick to the RAM area inside the system controller and are used.
4. Communication between System Controller IC722 and EEP ROM IC723
The EEP ROM IC723 stores the information that is set from the menu. In order to read the necessary data from the EEP ROM, the system controller IC722 outputs the serial
data (read command) from pin-69 [TXD2] of the system controller IC722 to pin-3 [DI] of the EEP ROM IC723 in synchronization with the clock of pin-70 [SCK2] and the chip
select signal of pin-1 [XEPCS] of the system controller IC722. When the EEP ROM IC723 receives the read command, it outputs the corresponding data from pin-4 [DO] to
pin-68 [RXD2] of the system controller IC722.
5. Communication between System Controller IC722 and Memory Stick
The system controller IC722 performs the serial communication with the controller that is installed inside the Memory Stick. The system controller IC722 outputs the various
commands to the Memory Stick from pin-12 [MS DIO] in synchronization with the clock output from pin-13 [MS CLK] and the bus state signal output from pin-11 [MS BS]. Role
of the controller inside the Memory Stick is described next. In order to read data from the Memory Stick, the controller inside the Memory Stick receives the data read command
first. Then it reads the data corresponding to the read command, from the FLASH RAM area inside the Memory Stick. The controller inside the Memory Stick then converts the
read-out data to the serial data and outputs it to the system controller IC722 in synchronization with the clock input from the system controller IC722 and the bus state signal.
The system controller IC722 converts the received data to the parallel data by its DMA controller and outputs the data to the 2M-bit S-RAM IC727 sequentially. In order to write
data into Memory Stick, the system controller IC722 outputs the data to be written in the controller inside the Memory Stick in the same manner as in reading, in synchronization
with the clock and bus state signal. The controller inside the Memory Stick that receives the data to be written, converts it to the parallel data and saves it in the FLASH RAM
area inside the Memory Stick.
Contents
Copying is strictly prohibited
6
71
1
2
3
4
7
6
8
78
68
69
70
24
25
11
17
12
13
2
1
3
17
18
19
IC164
ADPCM
DEN
EXCK
DIN
CS
SK
DI
DO
IC723
EEP ROM
XEPCS
IC721
REAL TIME CLOCK
MS BS
MSDIO MSCLK
MEMORY STICK
XLCDS
LCDDO
LCDDI LCDSCK
CS
SDA
SCL
LCD720 LCD MODULE
A1
.
.
.
D0
.
.
.
.
.
.
A17
.
.
.
D15
A0
.
.
.
I/O1
.
.
.
.
.
.
A16
.
.
.
I/O16
CLK
DATA
CE1
CE0
SCK2
TXD2
RXD2
RTCCE
64
62
.
59
54
.
52
.
50
44
108
105
.
103
96
.
94
.
92
89
25
18
.
8
1
.
48
29
36
.
38
45
IC722
SYSTEM CONTROLLER
IC727
S RAM
Fig. 1-2 Microprocessor interface
Copying is strictly prohibited
7
2. POWER SUPPLY CIRCUIT
2-1. Discriminating Power Supplies
This unit can be operated on the following two types of the power supply.
• AC adapter (Output 3.0 [V] type)
• Size AAA, alkaline dry cell battery x 2
The system controller IC722 identifies which of either AC adapter or battery is used as the main power, by monitoring the input voltages of pin-150 [XDCIN] and pin-173 [BATT].
The system controller IC722 identifies that this unit is operated on the battery when pin-150 [XDCIN] is “H” and that this unit is operated on the AC adapter when pin-150
[XDCIN] is “L”. When this unit is operated on the AC adapter, the battery's remaining amount indication is not displayed on the LCD. When the input voltage at pin-173 [BATT]
has decreased to about 1.5 [V] or less (i.e., voltage from the battery has decreased to about 2.0 [V]), the system controller IC722 displays the message “LOW BATT” on the
LCD and stops the operation of this unit. This unit does not have the over-voltage protection circuit.
2
3
1
173
150
D2
C2
T1
D1
C3
R6
IN
GND
OUT
IC1
VOLTAGE
DETECTOR
VOLTAGE
DETECTOR
When operating on battery: H
When operating on AC adapter: L
When operating on AC adapter: L
Q1
C9
R2
R1
BATT
XDCIN
UN REG 2.5[V]
IC722 SYSTEM
CONTROLLER
Fig. 2-1 Discrimination of power supply
Table 2-1 shows the discrimination of the power supplies. Table 2-2 shows the relationship between the battery output voltage and the LCD display of the remaining amount of
battery.
Table 2-1 Discrimination of Power Supplies Table 2-2 Battery voltage and LCD display
Pin-150 [XDCIN]
LCD display of the
remaining amount of battery
When operating on AC adapter
L No
When operating on alkaline dry cell battery
H Yes
If the power supply from the AC adapter to the unit is stopped due to some reasons while the unit
is operating on an AC adapter, and if a battery having the sufficient capacity of charge is inserted
in the unit, operation of the unit is continued because the negative polarity of the battery is
connected to ground through the diode D2. When the AC adapter resumes to supply the power
voltage from this status, operation of the unit is continued.
is operating on an AC adapter, and if a battery having the sufficient capacity of charge is inserted
in the unit, operation of the unit is continued because the negative polarity of the battery is
connected to ground through the diode D2. When the AC adapter resumes to supply the power
voltage from this status, operation of the unit is continued.
Display
Battery voltage
Pin-173 [IC722]
About 2.6 [V] or more
About 1.95 [V] or more
About 2.3 to 2.6 [V]
About 1.73 to 1.94 [V]
About 2.2 to 2.3 [V]
About 1.65 to 1.72 [V]
About 2.1 to 2.2 [V]
About 1.58 to 1.64 [V]
Contents
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8
2-2. Over-discharge Protection Circuit
VOLTAGE DETECTOR IC521 and Q521 have the function of over-discharge protection of battery. When the power input voltage at pin-3 [IN] of the VOLTAGE DETECTOR
IC521 has decreased to about 0.6 [V] (output voltage from battery is about 1.2 [V]) or less, the current flowing into the unit is limited by stopping the CE (chip enable) voltage to
the power controller IC522 and the +3.3 [V] regulator IC524 in order to protect battery from over-discharging.
2
3
1
2
3
3
41
1
Q521 2/2 is turned OFF when Q521 1/2 is turned
OFF so that the CE power supply to IC522 and
IC524 is stopped.
OFF so that the CE power supply to IC522 and
IC524 is stopped.
0 V when UN REG 2.5 [V] has decreased
to about 1.2 V or less
to about 1.2 V or less
IN
GND
OUT
UN REG 2.5[V]
R526
C521
R525
R527
VOLTAGE
DETECT
DETECT
Q521
1/2
1/2
R521
R522
R523
Q521
2/2
2/2
DC-DC CONVERTER
CONTROL
CONTROL
TO
IC522
POWER CONTROL
IC522
POWER CONTROL
TO
IC522
IC524
IC522
IC524
[CE]
[CE]
[S POWER]
FROM
IC722
IC722
R528
IC521
Fig. 2-2 Over-discharge protection circuit
Contents
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