Atmel SpaceWire Router SpW-10X User Manual

Ref.:   UoD_SpW-10X_ 

 

Issue:  3.4 

  

 

Date:  11

 

 

141

 

2.  LVDS fail safe resistors need not be adjacent to the termination resistor. Their location is 

not critical but the stub lengths to the termination resistors should be less than 20 mm. 

3.  LVDS tracks shall be 100 ohm differential impedance.  

4.  Skew between the plus and minus sides of the LVDS differential pair shall be avoided and 

shall be less than +/- 1 mm. 

5.  Data and strobe track lengths shall be matched to +/- 2.5 mm to keep skew to a minimum. 

6.  There is no need to match input and output track lengths. 

7.  Vias shall only be used at the SpaceWire connector and close to the SpW-10X device 

(within 5 mm). 

12.2.7 External Ports 

The following recommendations apply to the External FIFO port signals from the SpW-10X device: 

1.  When the External FIFO ports are used, series termination resistors (33 ohm) should be used 

on each output if the tracks on the outputs are more than 4 cm in length. 

2.  The series termination resistors should be placed as close as possible to the output pins of the 

SpW-10X device. 

3.  Series termination resistors are also recommended on the devices driving the External FIFO 

port inputs if the tracks connected to the inputs are more than 4 cm in length. 

4.  The pull up/down resistor recommendations provided in section 5.3 should be followed. 

12.2.8 Time-code Interface 

The following recommendations apply to the Time-code signals from the SpW-10X device: 

1.  When the time-code interface is used, series termination resistors (33 ohm) should be fitted to 

each output if the tracks on the outputs are more than 4 cm in length. 

2.  The series termination resistors should be placed as close as possible to the output pins of the 

SpW-10X device. 

3.  Series termination resistors are also recommended on the devices driving the time-code 

inputs if the tracks connected to these inputs are more than 4 cm in length. 

4.  The pull up/down resistor recommendations provided in section 5.4 should be followed. 

12.2.9  Status / Power On Configuration Interface 

The pull up/down resistor recommendations provided in section 5.6 should be followed for power on 
configuration.