Overview
The SM5903CF is a compression and non compression type anti-shock memory controller LSI for compact disc players. The compression level can be set in 4 levels, and external memory can be selected from 4 options (1M, 4M, 4M× 2, 16M). It operates from a 4.5 to 5.5 V supply voltage range.

Features
- 2-channel processing
- Serial data input
     • 2s complement, 16-bit/MSB first, rear-packed format
     • Wide capture function (until triple speed available)
- System clock input
     • 384fs (16.9344 MHz)
- Anti-shock memory controller
     • ADPCM compression method
     • 4-level compression mode selectable
        4-bit compression mode 2.78 s/Mbit
        5-bit compression mode 2.22 s/Mbit
        6-bit compression mode 1.85 s/Mbit
        Full-bit non compression mode 0.74 s/Mbit
     • 4 external DRAM configurations selectable 16M DRAM (4M × 4 bits ×1,refresh cycle 2048 cycle)
        4M DRAM (1M × 4 bits ×1 or ×2)
        1M DRAM (256k × 4 bits ×1)
- Microcontroller interface
     • Serial command write and state read-out
     • Data residual quantity detector: 15-bit operation, 16-bit output
     • Forced mute
- Extension I/O
    Microcontroller interface for external control using 5 extension I/O pins
- +4.5 to +5.5 V operating voltage range
- Schmidt inputs
    All input pins (including I/O pins) except CLK (system clock)
- Reset signal noise elimination
    Approximately 3.8 µs or longer (65 system clock pulses) continuous LOW-level reset
- 44-pin QFP package (0.8 mm pin pitch)