LC78625 Просмотр технического описания (PDF) - SANYO -> Panasonic

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Компоненты Описание

производитель

LC78625

Compact Disc Player DSP

SANYO -> Panasonic 

LC78625E

• Command noise rejection

Code

$EF

$EE

COMMAND

Command input noise reduction mode

Reset the above mode.

RES = L

q

This command reduces the noise on the CQCK clock signal. While this is effective for noise pulses shorter than 500

ns, the CQCK timings tWL, tWH, and tSU (see page 5, figures 1 and 2), must be set to be at least 1 µs.

6. Focus servo circuit; Pin 16: FOCS, pin 17: FST, pin 18: FZD, pin 70: LASER

Code

$08

$A2

$0A

$8A

$FE

COMMAND

FOCUS START #1

FOCUS START #2

LASER ON

LASER OFF

NOTHING

RES = L

q

The FOCS, FST, and FZD pins are not required when the LC78625E is used in combination with an LA9230/40

Series LSI. FZD should be connected to 0 V when these pins are not used. The LA9230/40 Series focus start

command is identical to the LC78625E FOCUS START #1 command.

• NOTHING

This command can be used to initialize the LC78625E by inputting FE (hexadecimal: Hexadecimal constants are

written with a dollar sign ($) prefix). Note that $00 is the reset command for the LA9230/40 Series, and should be

used with care since it clears the result of the automatic adjustment process and returns these chips to their initial

states.

• Laser control

The LASER pin can be use as an extended output port.

• Focus start

When the LC78625E is used in combination with an LA9230/40 Series LSI, the focus start operation is executed

completely on the servo side by commands from the control microprocessor. The following section describes this

operation when the LC78625E is used in combination with an LA9210M or LA9211M.

When a focus start instruction (either FOCUS START #1 or FOCUS START #2) is input as a servo command, first the

charge on capacitor C1 is discharged by FST and the objective lens is lowered. Next, the capacitor is charged by FOCS,

and the lens is slowly raised. FZD falls when the lens reaches the focus point. When this signal is received, FOCS is

reset and the focus servo turns on. After sending the command, the microprocessor should check the in-focus detection

signal (the LA9210 DRF signal) to confirm focus before proceeding to the next part of the program. If focus is not

achieved by the time C1 is fully charged, the microprocessor should issue another focus command and iterate the focus

servo operation.

No. 5502-12/35

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