GENERAL DESCRIPTION
The MSM7503 is a high performance, low power CODEC LSI device integrating a 2-wire time division transmission (ping-pong transmission) interface function and has a basic function of man-machine interface to that of the MSM7502.
The MSM7503 operates from single 5 V power supply and is ideal for digital telephone terminals such as pushbutton telephone sets and digital PBXs.

FEATURES
• Single +5 V Power Supply
• Low Power Dissipation
   Power ON Mode : 50 mW Typ.  100 mW Max.
   Power Down Mode : 15 mW Typ.    30 mW Max.
• Pin-Pong Transmission : Burst of 8 kHz, Transmission of 256 kbps,
                                  AMI coding, 2-wire time division transmission
• Transmission data configuration : Transmit Start bit (1 bit), K-bit (1 bit),
                                                          Control bit (2 bits), Voice bit (8 bits),
                                                          DC balance bit (1 bit), totalling 13 bits
                                              Receive Sync bit (4 bits), K-bit (1 bit),
                                                          Control bit (2 bits), Voice bit (8 bits),
                                                          DC balance bit (1 bit), totalling 16 bits
• Control Data Interface supports synchronous and asynchronous communications
• Built-in Power-on Reset by the power supply voltage monitoring
• Output of the ping-pong transmission monitoring signal
• CODEC complied by the ITU-T companding law
• Calling Tone Interval : Controlled by processor
• Calling Tone Combination : Controlled by processor, 6 modes
• Calling Tone Volume : Controlled by processor, 4 modes
• Ringing Tone Interval : Controlled by processor
• Ringing Tone Frequency : Controlled by processor, 6 modes
• Ringing Tone Level : Controlled by processor, 4 levels
• Built-in PB Tone Generator
• Built-in Speech path Control Switches
• General Latch Output for External Control : 2 bits
• Watch-dog Timer : 500 ms