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855PM Chipset Platform Design Guide
9.9.2.3.
Crosstalk Consideration ............................................................... 215
9.9.2.4.
Impedances .................................................................................. 215
9.9.2.5.
Line Termination........................................................................... 215
9.9.2.6.
Terminating Unused LAN Connect Interface Signals................... 215
9.9.3.
Intel 82562ET / Intel 82562 EM Guidelines................................................. 215
9.9.3.1.
Guidelines for Intel 82562ET / Intel 82562EM Component
Placement..................................................................................... 216
9.9.3.2.
Crystals and Oscillators................................................................ 216
9.9.3.3.
Intel 82562ET / Intel 82562EM Termination Resistors................. 216
9.9.3.4.
Critical Dimensions....................................................................... 217
9.9.3.4.1.
Distance from Magnetics Module to RJ-45 (Distance A)218
9.9.3.4.2.
Distance from Intel 82562ET / 82562ET to Magnetics
Module (Distance B)................................................... 218
9.9.3.5.
Reducing Circuit Inductance ........................................................ 218
9.9.3.5.1.
Terminating Unused Connections.............................. 219
9.9.3.5.2.
Termination Plane Capacitance ................................. 219
9.9.4.
Intel 82562ET/EM Disable Guidelines......................................................... 220
9.9.5.
Design and Layout Consideration for Intel 82540EP / 82551QM ............... 221
9.9.6.
General Intel 82562ET / 82562EM / 82551QM / 82540EP Differential Pair
Trace Routing Considerations ..................................................................... 221
9.9.6.1.1.
Trace Geometry and Length ...................................... 222
9.9.6.1.2.
Signal Isolation ........................................................... 222
9.9.6.1.3.
Magnetics Module General Power and Ground Plane
Considerations............................................................ 223
9.9.6.2.
Common Physical Layout Issues ................................................. 224
9.10.
Power Management Interface ..................................................................................... 225
9.10.1.
SYS_RESET# Usage Model ....................................................................... 225
9.10.2.
PWRBTN# Usage Model............................................................................. 225
9.10.3.
Power Well Isolation Control Strap Requirements ...................................... 225
9.11.
CPU I/O Signals Considerations ................................................................................. 226
10.
Platform Clock Routing Guidelines .......................................................................................... 229
10.1.
Clock Routing Guidelines ............................................................................................ 229
10.2.
Clock Group Topology and Layout Routing Guidelines .............................................. 232
10.2.1.
HOST_CLK Clock Group............................................................................. 232
10.2.1.1.
BCLK Length Matching Requirements ......................................... 234
10.2.1.2.
BCLK General Routing Guidelines............................................... 235
10.2.1.3.
EMI constraints ............................................................................. 235
10.2.2.
CLK66 Clock Group..................................................................................... 236
10.2.3.
AGPCLK Clock Group ................................................................................. 237
10.2.4.
CLK33 Clock Group..................................................................................... 238
10.2.5.
PCICLK Clock Group................................................................................... 239
10.2.6.
USBCLK Clock Group ................................................................................. 242
10.2.7.
CLK14 Clock Group..................................................................................... 243
10.2.8.
CK-408 Clock Chip Decoupling ................................................................... 243
10.3.
CK-408 Updates for Systems based on Intel Pentium M Processor / Intel Celeron M
Processor and Intel 855PM Chipset ........................................................................... 244
10.4.
CK-408 PWRDWN# Signal Connections.................................................................... 244
11.
Platform Power Delivery Guidelines ........................................................................................ 245
11.1.
Definitions.................................................................................................................... 245
11.2.
Platform Power Requirements .................................................................................... 246
11.2.1.
Platform Power Delivery Architectural Block Diagram ................................ 247
11.3.
Voltage Supply ............................................................................................................ 248