Overview

The SM5904BF is a compression and non compression type shock-proof memory controller LSI for compact disc players. The compression level can be set in 4 levels, and external 4M DRAM can be connected to expand the memory to 4M bits. Digital attenuator, soft mute and related functions are also incorporated. It operates from a 2.4 to 3.3 V supply voltage range.

Features

- 2-channel processing

- Serial data input

• 2s complement, 16-bit/MSB first, right-justified format

- Wide capture function (up to 3 × speed input rate)

- System clock input

• 384fs (16.9344 MHz)

- Shock-proof 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

• External DRAM configurations usable

2 × 4M DRAM (1M × 4 bits)

Internal and External 4M DRAM

1 × 4M DRAM (1M × 4 bits)

Only Internal 4M DRAM

- Compression mode selectable

- Microcontroller interface

• Serial command write and status read-out

• Data residual detector: 15-bit operation, 16-bit output

• Digital attenuator 8-bit setting

• Soft attenuator function

Noiseless attenuation-level switching (256- step switching in 23 ms max.)

• Soft mute function

Mute ON in 23 ms max.

Direct return after soft mute release

• Forced mute

- Extension I/O

Microcontroller interface for external control using 4 extension I/O pins

- +2.4 to + 3.3 V operating voltage range

- Schmitt 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

- Digital audio interface (DIT)

- 44-pin QFP package (0.8 mm pin pitch)