Initial Sled Motor Drive; Initial Sled Movement - Sony DVP S530D Training Manual

Initial Sled Motor Drive

Initial Sled Movement

Start
When the laser's platform is lifted to a level position, the disc is sand-
wiched between the spindle motor table and the magnet. In this position
the disc is said to be "chucked". The chucked position requires System
Control IC202 to retrieve the initial sled program stored in EEProm memory
IC201 (not shown) via the parallel bus.
Movement
The program in IC201 instructs the sled motor to move the laser to home
position then quickly outward, but the sled does not stop. It just slows
down while the laser and focus search is activated. If a disc is found, the
sled stops and playback begins. However, if no disc is found, the sled
speeds up and moves outward again further into the disc area. As it
slows down a second time, the laser and focus system is instructed to
look for a disc (specifically its information layer). If it fails to find it, the sled
is quickly moved outward the last time for the third search. The "no disc
found" cycle concludes when the sled motor is reversed and the laser
assembly is driven home.
ICs Used
System Control IC202 controls the sled motor during this initial disc search
stage. A series of ICs are used for this control:
· System Control IC202 uses HGA IC601 as an expansion port
· HGA IC601 instructs Servo DSP IC701
· Servo DSP IC701 issues analog commands to Driver IC802
· Sled Driver IC802 sends voltages to the stepper sled motor
System Control IC202 uses HGA IC601
System Control IC202 plans out the DVD operations, but turns the details
of each operation over to a partner IC. It is much like a manager who
starts many projects, but has the details of each project finished by a
subordinate. When there are too many projects, the manager needs help
from an assistant manager to help oversee the activity. System Controls
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IC202 employs expansion port Hybrid Gate Array (HGA) IC601 for assis-
tance in managing the remaining ICs.
IC202 to IC601 Communications
When IC202 wants to send data to IC601, IC202 must also send chip
select, clock, write pulses and address information to support the data.
IC202 to IC601 Communications Signals
Signal
Chip Select (CS1 or CS4
from IC202/pins 10 or 7))
Clock IC202/pin 5
Write IC202/pin 22
Six Address lines HA 0-5
16 Data lines HD 0-15
IC601 to IC202 Communications
When IC601 wants to send reply data to IC202, an interrupt signal is sent
to IC202. When IC202 is ready, it will send chip select, clock, read pulses,
and address to support the data received from IC601.
IC601 to IC202 Communications
Signal
Interrupt (INT1 or INT3)
Chip Select (CS1 or CS4)
Clock IC202/pin 5
Read IC202/pin 24
Six Address lines HA 0-5
16 Data lines HD 0-15
HGA IC601 Instructs Servo DSP IC701
IC601 controls many ICs. One of them is Servo DSP IC701. Communi-
cations between these ICs use four control lines to transfer the address
and data on the parallel bus:
Active Signal Present When:
Low IC202 & IC205 gets Vcc
Low IC202 gets B+
Low IC202 & IC205 gets Vcc
IC202 gets B+
IC202 gets B+
Active Signal Present When:
Low An operation is completed
(e.g. sled moved)
Low IC202 & IC205 gets Vcc
Low IC202 gets B+
Low IC202 & IC205 gets Vcc
IC202 gets B+
IC202 gets B+