CL-CR3470/CR3475
ATAPI CD-R/RW Encoder/Decoder
OVERVIEW (cont.)
multi-session-at-once. These devices incorporate the
most comprehensive error correction available in the
industry, using realtime CD-ROM-layered ECC error
correction with a programmable number of P/Q-word
corrections per sector (up to 64 total). The
CL-CR3470/CR3475 also supports realtime subcode
R-W correction in CD-DA™ mode. Other hardware-
enabled features include automatic target-header
search, sector-header validity check during data
transfer, programmable pseudo-sync mark insertion
for sector synchronization, and automated CD-R
packet disc read (Method 1 and Method 2). The
CL-CR3470/CR3475’s DSP interface supports
CD-ROM DSPs from numerous manufacturers. The
DSP interface includes three types of interface signals:
main data channel signals, subcode channel signals,
and serial DSP programming signals.
between the external DRAM data buffer and all other
internal blocks.
These interfaces store and retrieve data to/from exter-
nal buffer memory using interleaved access.
In addition, the CL-CR3470/CR3475 supports stream-
ing mode and the hardware automation of concurrent
host and disc transfers from the same buffer segment.
These features ease firmware programming and
decrease microcontroller intervention.
The highly automated and optimized ATAPI interface is
designed for compliance with the ATAPI specification.
The ATAPI Command and Control Block registers are
contained in the CL-CR3470/CR3475 register set,
which allow both the host and local microcontroller
access. The CL-CR3470/CR3475 supports ATAPI
protocols by hardware without microcontroller
intervention.
The integrated formatter is a built-in control processor
that executes formatter instructions stored in the buffer
memory, controls the CD-ROM encoder, and specifies
how each block is generated/encoded through an
entire recording operation. The built-in high-perfor-
mance buffer manager controls the flow of data
The CL-CR3470 is available in a 144-pin LQFP pack-
age, and the CL-CR3475 is available in a 176-pin
LQFP package.
ADVANTAGES
Unique Features
Benefits
■ Supports disc speeds up to 40x read and 10x write
❒ Enables the highest-performance CD-R/RW drives
❒ Allows headroom for future speed requirements
without a complete system redesign
■ Single-chip integration of CD-ROM
encoder/decoder, CIRC encoder, EFM modulator,
ATIP decoder, buffer manager, and host interface
logic
❒ Reduces cost, board space, chip count, and
interconnections
❒ Eases system design and firmware development
■ Realtime ECC correction (up to 64 P/Q-word
corrections/sector) and Erasure Pointer correction,
with no microcontroller intervention
❒ Improves system performance, reduces firmware
overhead and microcontroller performance
requirements, and improves reliability and correction
capability
■ Realtime subcode error R-W correction in CD-DA
❒ Exceeds advanced ECC requirements of state-of-the-
art CD-ROM designs for a variety of
mode
media/performance combinations
❒ Allows headroom for future ECC requirements
without a complete system redesign
■ Unique DVD port (CL-CR3475 only)
❒ Enables CD-RW devices that also read DVD
CIRRUS [ CIRRUS LOGIC ]
