LC78624E Datasheet, PDF (1/27 Pages) Sanyo Semicon Device – Compact Disc Player DSP

Ordering number : EN5811
CMOS LSI
LC78624E
Compact Disc Player DSP
Overview
The LC78624E is a CMOS LSI that implements the signal
processing and servo control required by compact disc
players. Including an EFM-PLL and text decoder, the
LC78624E strictly limits functionality to basic signal
processing and servo system operation to achieve the best
cost-performance balance for low-end players. As basic
functions, the LC78624E provides demodulation of the
EFM signal from the optical pickup, de-interleaving, error
detection and correction, and processes servo commands
sent from the control microcontroller.
Functions
• Input signal processing: The LC78624E takes an HF
signal as input, digitizes (slices) that signal at a precise
level, converts that signal to an EFM signal, and
generates a PLL clock with an average frequency of
4.3218 MHz by comparing the phases of that signal and
an internal VCO.
• Precise reference clock and necessary internal timing
generation using an external 16.9344 MHz crystal
oscillator
• Disk motor speed control using a frame phase difference
signal generated from the playback clock and the
reference clock
• Frame synchronization signal detection, protection and
interpolation to assure stable data readout
• EFM signal demodulation and conversion to 8-bit
symbol data
• Subcode data separation from the EFM demodulated
signal and output of that data to an external
microcontroller
• Subcode Q signal output to a microcontroller over the
serial I/O interface after performing a CRC error check
(LSB first)
• Serial output to a microcontroller via the text decoder of
the song titles and other text data stored in the Subcode
R through W channels of the read-in area
• Demodulated EFM signal buffering in internal RAM to
handle up to ±4 frames of disk rotational jitter
• Demodulated EFM signal reordering in the prescribed
order for data unscrambling and de-interleaving
• Error detection, correction, and flag processing (error
correction scheme: dual C1 plus dual C2 correction)
• The LC78624E sets the C2 flags based on the C1 flags
and a C2 check, and then performs signal interpolation
or muting depending on the C2 flags. The interpolation
circuit uses a dual-interpolation scheme. The previous
value is held if the C2 flags indicate errors two or more
times consecutively.
• Support for command input from a microcontroller:
commands include track jump, focus start, disk motor
start/stop, muting on/off and track count (8 bit serial
input)
• Built-in digital output circuits.
• Arbitrary track counting to support high-speed data
access
• Zero cross muting
• Supports the implementation of a double-speed dubbing
function.
• Support for bilingual applications.
• General-purpose I/O ports: 5 pins
Features
• 64 pin QFP
• 5 V single-voltage power supply
Package Dimensions
unit: mm
3159-QFP64E
[LC78624E]
SANYO: QIP64E
SANYO Electric Co.,Ltd. Semiconductor Bussiness Headquarters
TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110-0005 JAPAN
20698RM (OT) No. 5811-1/27