EP80579 Datasheet, PDF (1619/1916 Pages) Intel Corporation – Intel® EP80579 Integrated Processor Product Line

Intel^® EP80579 Integrated Processor
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41.1
41.2
IEEE 1588 Time Synchronization Hardware Assist
Overview
This document describes the hardware-assist logic developed to achieve time
synchronization on Ethernet and CAN.
In a distributed control system containing multiple clocks, individual clocks tend to drift
apart. Some kind of correction mechanism is necessary to synchronize the individual
clocks to maintain global time, which is accurate to some requisite clock resolution. For
this purpose, you can use the IEEE 1588 standard, which defines a precision clock
synchronization protocol for networked measurement and control systems. The IEEE
standard defines several messages that you can use to exchange timing information.
The hardware assist logic, required to achieve precision clock synchronization using the
IEEE 1588 standard, is left to the implementation.
The time synchronization logic monitors the internal MII and GMII signals on the
Gigabit Ethernet controller. Only Gigabit port 0 and port 1 are supported. The interrupt
signals from CAN will also be monitored to allow CAN traffic to be time-stamped as
well.
An interrupt signal to the host processor is generated by the 1588 Time Sync block
when any of the following conditions occur and are enabled:
• Target Time expiration
• Auxiliary Target Time expiration
• Auxiliary Master Mode snapshot is taken
• Auxiliary Slave Mode snapshot is taken
• Pulse Per Second signal assertion
The System Time, Target Time and Aux Target Time registers are all 64 bits wide. When
the system time is greater than or equal to the target time, the target time expiration
condition will set. An interrupt enable mask must be set to allow the target time
interrupt to pass to the core.The Aux Target Time register works the same as the Target
Time register.
Feature List
A list of features is presented below:
• Supports IEEE1588-2008.
• Supports user-defined messages.
• Supports detection of IEEE 1588 messages for both receive and transmit directions.
• Supports Ethernet MII and GMII.
• Supports CAN 2.0B.
• Provides external signals to signify if a snapshot was taken.
• Provides external control over taking snapshots.
August 2009
Order Number: 320066-003US
Intel^® EP80579 Integrated Processor Product Line Datasheet
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