Design Guide
49
Platform Clock Routing Guidelines
4.1.6
USBCLK Clock Group
For the USBCLK clock group, the driver is the clock synthesizer USB clock output buffer, and the
receiver is the USB clock input buffer at the ICH3-S. Note that this clock is asynchronous to any
other clock on the board.
Figure 4-14. Topology for USB_CLK
Table 4-9. USBCLK Routing Guidelines
Parameter
Routing Guideline
Clock Group
USBCLK
Topology
Point-to-Point
Reference Plane
Ground referenced (contiguous over entire length)
Characteristic Trace Impedance (Z
0
)
50
Ω
± 10%
Trace Width
5 mils
Trace Spacing
25 mils
Trace Length – L1
0.00” – 0.50”
Trace Length – L2
3.00” – 12.00”
Resistor
R1 = 33
Ω
± 5%
Skew Requirements
None – USBCLK is asynchronous to any other clock on the board
Maximum Via Count
2
R1
L1
L2
Intel
®
ICH3-S
Clock
Driver
Содержание Xeon
Страница 24: ...Introduction 24 Design Guide This page is intentionally left blank ...
Страница 30: ...Component Quadrant Layout 30 Design Guide This page is intentionally left blank ...
Страница 34: ...Platform Stack Up and Component Placement Overview 34 Design Guide This page is intentionally left blank ...
Страница 52: ...Platform Clock Routing Guidelines 52 Design Guide This page is intentionally left blank ...
Страница 66: ...System Bus Routing Guidelines 66 Design Guide This page is intentionally left blank ...
Страница 118: ...Intel 82870P2 P64H2 118 Design Guide This page is intentionally left blank ...
Страница 146: ...I O Controller Hub 146 Design Guide This page is intentionally left blank ...
Страница 148: ...Debug Port 148 Design Guide This page is intentionally left blank ...
Страница 210: ...Schematic Checklist 210 Design Guide This page is intentionally left blank ...
Страница 220: ...Layout Checklist 220 Design Guide This page is intentionally left blank ...
Страница 222: ...Schematics 222 Design Guide This page is intentionally left blank ...