Atmel SpW-10X Time-code Jitter, 10.6.6 200M bits/s Input and Output Bit Rate Example, User Manual

SpW-10X	Ref.:	UoD_SpW-10X_
SpaceWire Router		UserManual
	Issue:	3.4
User Manual
	Date:	11th July 2008

10.6.5 Time-code Jitter

The variation in time to propagate a time-code through a routing switch.

Time-code jitter occurs in the synchronisation handshaking circuits and the transmitter where the maximum delay time the time-code has to wait to be transmitted is one data character. The jitter is measured as

TTCJIT = (2⋅TSYSPERIOD)+ (5⋅TTXPERIOD)

10.6.6 200M bits/s Input and Output Bit Rate Example

The following table defines the latency and jitter measurements when the transmit bit rate and receive bit rate are 200M bits/s.

Table 10-6 SpaceWire Router Latency and Jitter Measurements (Bit rate = 200Mbits/s

Description	Symbol	Value	Units
Switching Latency	TSWITCH	133.3	ns, max
Router Latency – SpaceWire to SpaceWire port	TSSDATA	546.6	ns, max
Router Latency – SpaceWire to External port	TSEDATA	316.6	ns, max
Router Latency – External to SpaceWire port	TESDATA	363.3	ns, max
Router Latency – External to External port	TEEDATA	166.6	ns, max
Time-code Latency – SpaceWire to SpaceWire port	TSSTC	409.3	ns, max
Time-code Latency – SpaceWire to External port	TSETC	316.6	ns, max
Time-code Latency – External to SpaceWire port	TESTC	359.9	ns, max
Time-code Jitter	TTCJIT	116.6	ns, max
[1] Note all figures are worst case

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