Overview

The LC89512W integrates a real-time error correction circuit and a SCSI interface in a single chip.

Features

• Support for double-speed drives at an operating

frequency of 16.9344 MHz

Either SRAM (120 ns), DRAM (80 ns) or pseudo

SRAM (85 ns) can be used.

• Support for quad-speed drives at an operating frequency

of 33.8688 MHz

SRAM (70 ns) must be used.

• Built-in SCSI interface with built-in 48 mA sink buffer

(Only the TARGET function is supported.)

• Built-in 12-byte output FIFO for sub-CPU to host

computer data transmission

• Built-in 12-byte input FIFO for host computer to subCPU data transmission

• Subcode data can be written to buffer RAM and the subCPU can read the subcode values by connecting the

LC89512 to the CD-DSP subcode pin.

• Sub-CPU access of buffer RAM through the LC89512

• Built-in function for buffer RAM internal data transfer

• Pseudo-SRAM (128-kword × 8-bit and smaller) can be

used.

• DRAM (two 256-kword × 4-bit chips or two 1-Mword ×

4-bit chips) can be used.

• Transfer speeds:

2.8 MB/second (asynchronous mode) (for CD-ROM

decode only operation)

4.2 MB/second (synchronous mode) (CD-ROM decode

operation is not supported in synchronous mode)

Both of these transfer modes use a 16.9344 MHz clock.

(The transfer speed depends on the frequency used.)

• Operating frequencies: 16.9344 MHz (up to double

speed), 33.8688 (quad speed)

Functions

• CD-ROM error correction function, subcode readout function, SCSI interface