X-Stream Operator’s Manual 
WM-OM-E Rev I  15 
Notes on Using Channel Emulation without Reference........................................................ 374 
Channel Emulation with Reference ........................................................................... 375 
Notes on Using Channel Emulation with Reference............................................................. 377 
Using Analog Compare.............................................................................................. 378 
Notes on Using Head/Analog Compare................................................................................ 379 
Local Feature Concepts............................................................................................. 380 
Overview ............................................................................................................................... 380 
Peak-Trough Identification.................................................................................................... 381 
Local Baselines..................................................................................................................... 381 
Setting Hysteresis ................................................................................................................. 383 
Local Parameters.................................................................................................................. 383 
Local Feature Parameters ......................................................................................... 385 
Disk Standard Parameters......................................................................................... 400 
Disk PRML Parameters ............................................................................................. 408 
Noise Parameters...................................................................................................... 417 
PRML Channel Emulation ......................................................................................... 420 
Why PRML?.......................................................................................................................... 420 
Principle of Equalization........................................................................................................ 421 
-3 dB Frequency ................................................................................................................... 422 
Boost at fc ............................................................................................................................. 422 
Group Delay.......................................................................................................................... 423 
Resampling ADC .................................................................................................................. 424 
Finite Impulse Response (FIR) ............................................................................................. 424 
Phase Locked Loop (PLL) .................................................................................................... 424 
Automatic Gain Control (AGC) ............................................................................................. 425 
PLL and AGC........................................................................................................................ 426 
ML Detector .......................................................................................................................... 426 
Viterbi Detector & Trellis ....................................................................................................... 426 
SAM ...................................................................................................................................... 426 
Encoding ............................................................................................................................... 427 
Error Correction .................................................................................................................... 427 
User Defined Trellis ................................................................................................... 427 
File Format and Language (version 1).................................................................................. 427 
Loading Your UDT File Remotely ......................................................................................... 428 
Example File ......................................................................................................................... 434