Atmel SpW-10X Pcb Design And Layout Guidelines, 12.2.1 CLK, Rstn, Chip Test Signals, Ground

Models: SpW-10X

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12.2 PCB DESIGN AND LAYOUT GUIDELINES

SpW-10X

SpaceWire Router

User Manual

12.2 PCB DESIGN AND LAYOUT GUIDELINES

PCB design and layout guide lines are provided in this section.

12.2.1 CLK

1.Series termination should be used on the CLK signal.

2.Stubs on the CLK signal shall not be used.

Ref.: UoD_SpW-10X_

UserManual

Issue: 3.4

Date: 11th July 2008

3.Guard tracks shall be provided around the CLK signal trace connected to the ground plane approximately every 1 cm.

12.2.2 RST_N

Guard tracks shall be provided around the RST_N signal trace connected to the ground plane approximately every 1 cm.

12.2.3 Chip Test Signals

The two chip test signals TestIOEn and TestEn shall both be tied directly to the ground plane.

12.2.4 Power and Decoupling

1.Each power pin shall be decoupled to ground using a 100 nF decoupling capacitor.

2.The 100 nF decoupling capacitors shall be fitted close to the each power pin with the other end of the capacitor connected to the ground plane.

3.In addition to the 100 nF decoupling capacitors four 1 µF decoupling capacitors shall be fitted close to the SpW-10X device.

12.2.5 Ground

1.A solid ground plane shall be used.

2.The ground pins of the SpW-10X shall be directly connected to the ground plane using vias close to the SpW-10X ground pins.

12.2.6 SpaceWire

The following recommendations apply to all the SpaceWire signals from the SpW-10X device (see also section 5.2):

1. LVDS receiver termination resistor shall be as close as possible to the receiver inputs.

Preliminary

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Atmel SpW-10X Pcb Design And Layout Guidelines, 12.2.1 CLK, Rstn, Chip Test Signals, Power and Decoupling, Ground