Sony ODS-D77F Service Manual Download

Page: 33 / 104

1-17. Circuit Description

1-17-1. Data Writing/Reading System

Data reading system

The RF signal of channel 0a read from the disc is transferred from the optical block to the Disc Drive LSI (IC100) on
the BD-44 board where AGC and equalizing correction is applied to the signal. Then the RF signal is converted to a
digital signal synchronizing the read clock generated in synchronization by the Read PLL.
After that, PR equalization, Viterbi decoding, 1-7PP demodulation, descrambling, decode (error correction), and other
processing are applied to the signal, and then the processed signal is sent to BRIDGE (IC700) with the SATA Interface.
In the same way, the RF signal of channel 0b/1a/1b is also processed by the Disc Drive LSI (IC200) on the BD-44 board,
and is then sent to BRIDGE (IC700).
The ODS-D77U controls four channel read signals and integrates them into a single channel with BRIDGE (IC700) to
produce the maximum transfer rate, and then sends the signal to the IF-1234 board.
The SATA-USB3.0 BRIDGE (IC3) on the IF-1234 board converts the SATA signal to a USB3.0 signal, and the USB3.0
signal is output from the USB connector (CN3).
The ODS-D77F controls four channel read signals and integrates them into a single channel with BRIDGE (IC700) to
produce the maximum transfer rate, and then sends the 4-lane PCIe 1.0 signal to the FC-116 board.
In the FC-116 board, the PCIe 1.0 signal is sent through the PCIe switch (IC2000) to the FC controller (IC1000) that is
controlled by the CPU (IC3000). The signal output from the FC controller is converted to an optical signal in the optical
module (SFP+) (CN1000), and the optical signal is output to the host.

Address reading system

The address information read from the disc is sent from the optical block to the Disc Drive LSI (IC100, IC200) on the
BD-44 board.
The Disc Drive LSI detects a wobble signal and decodes the address.
The detected analog wobble signal is converted to a digital signal, and a wobble clock (WCK) signal is generated by
the digital PLL.

Data writing system

In the ODS-D77U, the writing signal that is sent from the host to the USB connector (CN3) on the IF-1234 board is
converted to the SATA signal in the USB3.0-SATA bridge (IC3), and the SATA signal is sent to BRIDGE (IC700) on
the BD-44 board.
In the ODS-D77F, the writing signal that is sent from the host to the optical module (SFP+) (CN1000) on the FC-116
board is converted to the 4-lane PCIe 1.0 signal in the FC controller (IC1000) that is controlled by the CPU (IC3000).
Then the PCIe 1.0 signal is sent through the PCIe switch (IC2000) to BRIDGE (IC700) on the BD-44 board.
BRIDGE (IC700) controls distribution of Write system of four channels individually to produce the maximum transfer
rate.
Each distributed writing signal is input to the Disc Drive LSI (IC100, IC200, IC300, IC400) of each channel where
encode, scrambling and 1-7PP modulation processing are applied to the signal. Then the processed signal is sent to the
LDD in the optical block with the Write Strategy that meets each media type, and then the signal is written in the disc.

1-17-2. Servo System

Three-axis actuator and SA actuator

The objective lens in the optical block is controlled by the 3-axis actuator in the focus direction, in the track direction,
and for tilt.
The light reflected by the disc is converted to electrical signals by the optical block, and they are input to the Disc Drive
LSI (IC100, IC200, IC300, IC400) of each channel on the BD-44 board where a focus error signal and a track error
signal are generated.
The control amount is output from the Disc Drive LSI (IC100, IC200, IC300, IC400) to the driver (IC104, IC204, IC304,
IC404) to control the focus/tilt/SA actuators. The control amount is output to driver (IC500), and the track is controlled.

ODS-D77U/ODS-D77F

1-23