SM5904CF
NIPPON PRECISION CIRCUITS INC.
compression and non compression type
shock-proof memory controller
Overview
The SM5904CF is a compression and non com-
pression 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 2.5 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
- +2.5 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)
Ordering Information
SM5904CF
44pin QFP
NIPPON PRECISION CIRCUITS-1
NPC [ NIPPON PRECISION CIRCUITS INC ]
