E2D0026-27-43
¡ Semiconductor
MSM6688/6688L
ADPCM Solid-State Recorder IC
This version: Jan. 1998
Previous version: May. 1997
GENERAL DESCRIPTION
The MSM6688/6688L is a “solid-state recorder” IC developed using the ADPCM method. By
externally connecting a microphone, a speaker, a speaker drive amplifier, and a dedicated register
to store ADPCM data, it can record and play back voice data in a manner similar to a tape recorder.
The MSM6688 supports 5 V operation and has a stand-alone mode and a microcontroller interface
mode.
The MSM6688L supports 3 V operation and controls recording/playback in microcontroller interface
mode.
In the stand-alone mode, recording/playback conditions can be selected by pins and the MSM6688/
6688L can be controlled by a simple drive timing. In the microcontroller interface mode, recording/
playback can be controlled by commands from the microcontroller. In the microcontroller interface
mode, the MSM6688/6688L is much more flexible than in the stand-alone mode.
In addition, the MSM6688/6688L can form easily a recording and playback circuit with fixed
messages by connecting serial registers and serial voice ROMs as external memories.
Note: This data sheet explains a stand-alone mode and a microcontroller interface mode, separately.
Differences Between MSM6688 and MSM6688L
Parameter
Operating voltage
Control mode
Full scale of A/D and D/A
converters
Voice detection level for voice
triggered starting
External-only register
MSM6688
3.5 to 5.5 V
Standalone mode,
Microcontroller interface mode
0 to V
DD
± V
DD
, ± V
DD
, ± V
DD
64
32
16
32M bits (max.)
4M bits (MSM6684B)
8M bits (MSM6685)
MSM6688L
2.7 to 3.6 V
Microcontroller interface
mode only
1 V to 3 V
DD
DD
4
4
± V
DD
, ± V
DD
, ± V
DD
128
64
32
4M bits (max.)
4M bits (MSM66V84B)
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¡ Semiconductor
MSM6688/6688L
CONTENTS
(2) MICROCONTROLLER INTERFACE
MODE
(for MSM6688 (5 V Version)
FEATURES ........................................................ 3
and MSM6688L (3 V Version))
FEATURES ....................................................... 44
BLOCK DIAGRAM ......................................... 45
PIN CONFIGURATION ................................. 46
PIN DESCRIPTIONS ...................................... 47
ABSOLUTE MAXIMUM RATINGS
(for MSM6688 (5 V Version)) ......................... 50
RECOMMENDED OPERATING CON-
DITIONS (for MSM6688 (5 V Version)) ....... 50
ELECTRICAL CHARACTERISTICS
(for MSM6688 (5 V Version)) ......................... 50
ABSOLUTE MAXIMUM RATINGS
(for MSM6688L (3 V Version)) ...................... 55
RECOMMENDED OPERATING CONDITIONS
(for MSM6688L (3 V Version)) ...................... 55
ELECTRICAL CHARACTERISTICS
(for MSM6688L (3 V Version)) ...................... 55
TIMING DIAGRAMS ..................................... 60
FUNCTIONAL DESCRIPTION .................... 79
Recording Time and Memory
Capacity ................................................. 79
Connection of an Oscillator ...................... 79
Power Supply Wiring................................ 81
Analog Input Amplifier Circuit .............. 81
Connection of LPF Circuit
Peripherals ............................................ 82
LPF Characteristics .................................... 82
Full Scale of A/D and D/A Converters . 83
Reset Function ............................................ 84
Power Down by the
PDWN
pin .............. 85
Record/Playback Control Modes ........... 86
Data Configuration of External Serial
Registers ................................................ 88
Data Configuration of External
Serial Voice ROMs ............................... 97
Command Description .............................. 99
Status Register .......................................... 108
Inputting the Commands ....................... 112
Changes of Record/Playback
Conditions ........................................... 116
Setting and Confirming the
Record/Playback Conditions ................ 117
Flex Record/Playback Method .............. 128
Direct Record/Playback Method ......... 135
ROM Playback by Inputting Address
Code ..................................................... 138
Direct ROM Playback Method ............... 142
Stopping Record/
Playback Temporarily ....................... 144
Transferring Data to/from External
Memories ............................................. 145
Record/playback by Inputting/
Outputting Voice Data via Data Bus ........ 151
Suppression of Pop Noise at
AOUT Output ..................................... 155
APPLICATION CIRCUIT ............................ 157
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(1) STAND-ALONE MODE
(for MSM6688 (5 V Version))
BLOCK DIAGRAM .......................................... 4
PIN CONFIGURATION .................................. 5
PIN DESCRIPTIONS ....................................... 6
ABSOLUTE MAXIMUM RATINGS ............ 10
RECOMMENDED OPERATING
CONDITIONS ................................................. 10
ELECTRICAL CHARACTERISTICS ........... 11
TIMING DIAGRAMS .................................... 15
FUNCTIONAL DESCRIPTION ................... 28
Recording Time and Memory
Capacity ................................................ 28
Connection of an Oscillator ..................... 28
Power Supply Wiring............................... 29
Analog Input Amplifier Circuit ............. 29
Connection of LPF Circuit
Peripherals ........................................... 30
LPF Characteristics ................................... 31
Reset Function ........................................... 32
Power Down by the
PDWN
pin ............. 33
Record/Playback Control Mode ............ 34
Deleting phrases ....................................... 36
Recording Method .................................... 37
Playback Method ...................................... 38
ROM Playback Method ............................ 39
Voice Triggered Starting .......................... 40
Method of Temporarily Stopping Record/
Playback by Pause Function .............. 42
APPLICATION CIRCUIT ............................. 43
¡ Semiconductor
MSM6688/6688L
(1) STAND-ALONE MODE (for MSM6688 (5 V Version))
FEATURES
• 3-bit or 4-bit ADPCM
• Built-in 12-bit AD converter
• Built-in12-bit DA converter
• Built-in microphone amplifier
• Built-in low-pass filter
Attenuation characteristics –40 dB/oct
• External memories
Serial registers, 32M bits maximum (for variable messages)
8M bit serial register (MSM6685) can be driven directly
Serial voice ROMs, 4M bits maximum (for fixed messages)
1M bit serial voice ROM (MSM6595A) can be driven directly
2M bit serial voice ROM (MSM6596A) can be driven directly
3M bit serial voice ROM (MSM6597A) can be driven directly
• Sampling frequency
4.0 kHz, 5.3 kHz, 6.4 kHz or 8.0 kHz (master clock frequency = 4.096 MHz)
8.0 kHz, 10.6 kHz, 12.8 kHz, or 16.0 kHz (master clock frequency = 8.192 MHz)
• Number of phrases
63 phrases for variable messages
63 phrases for fixed messages
• Maximum recording time (when external 32M bit RAM is connected)
34 minutes (for 16 kbps ADPCM)
23 minutes (for 24 kbps ADPCM)
17 minutes (for 32 kbps ADPCM)
• Voice triggered starting function
• Pause function
• Master clock frequency: 4.096 MHz~8.192 MHz
• Power supply voltage: Single 5 V power supply
• Package:
56-pin plastic QFP (QFP56-P-910-0.65-2K) (Product name: MSM6688GS-2K)
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