Samsung DVD-R155 Service Manual page 121

4) Servo Features
◆ H/W
ΠDownloadable 16Kwords Program RAM
´ Built-in 10Bit ADC, 4ch Sample&Hold DAC X 2
ˇ Track Counter : Long Direct Seek
¨ Shock / Defect Detect
ˆ De_track Detect
Ø Header(DVD-RAM)/LAND Pre-Pit(DVD-R/RW) Detect
∏ Servo Monitor Signal
" RF IC , Elantec IC serial Interface
' Micom Interface : NEC and HITACHI Micom I/F Method Com compatible
◆ S/W
ΠDigital Servo Controller (Focus, Tracking, Sled Comove, Seek Controller)
´ DDT , Focus/Tracking Pull_in
ˇ Eccentricity/Deviation Detect
¨ Auto Calibration : Focus/Tracking Loop Offset/Balance/Loop Gain Adjustment
ˆ Seek
Ø Step Motor Control : Macro Seek
∏ De-track Compensation
" Center Servo
' DVD Layer Jump
˝ Shock/Defect Detect
Ô Tilt Control
5) PRML Features
ΠA/D converter
6Bits A/D Converting for Digital Data Sampling:5bit ENOB at 100MHz Input signal(guaranteed) Max.
Sampling Frequency of 240Mhz
Offset Binary Form of Sampling Data Output
´ Digital DC Offset Compensation : DSV Check
ˇ 11-Tap Gain Adaptive PR Filtering(LMS Algorithm)
¨ PR(a,b,b,a) Type Radix-16 Viterbi Detector (Flexible Type)
ˆ Digital Frequency & Phase Error Detection with DAC PLL Controller
Ø Blank/Defect Detect function
∏ Jitter Monitor(Digital Output)
" Raw Sync & Common Sync Monitoring Output
' DVD RW/R, RAM Wobble PLL
Samsung Electronics
Circuit Operating Descriptions
13-21