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IXP400 Software
Access-Layer Components: Time Sync (IxTimeSyncAcc) API
April 2005 IXP400 Software Version 2.0 Programmer’s Guide
290 Document Number: 252539, Revision: 007
• Internal errors
IxTimeSyncAcc returns IX_SUCCESS when errors are not observed. The client application is
expected to handle these errors/values appropriately.
20.4 IxTimeSyncAcc API Usage Scenarios
The following scenarios present usage examples of the interface by a client application. They are
each independent but, depending on the needs of the client application, could be intermixed.
20.4.1 Polling for Transmit and Receive Timestamps
The IEEE 1588 Hardware Assist block detects a PTP message and then sets an event flag. The
client application may poll for receive and/or transmit timestamps before or after the actual Sync/
Delay_Req message detection, which sets the event flags. The timestamps returned are valid only
when the respective event flags are set. After the valid timestamps are retrieved, the event flags are
cleared to allow for capturing new timestamps.
The IEEE 1588 Hardware Assist block indicates the availability of transmit and receive
timestamps on the MII interfaces through events only. In other words, interrupts are not defined for
these conditions (unlike the auxiliary timestamps and target time reached conditions, described
later). The client application has to poll for these events to obtain the timestamps.
Figure 97 presents the timestamp polling flow.
.
20.4.2 Interrupt Mode Operations
The IxTimeSyncAcc component uses a single interrupt on IXP46X network processors to provide
the client application with Target Time hit conditions or Auxiliary Master/Slave Timestamps. It
implements the following priority order when the interrupt is asserted to the Intel XScale core:
1. Target Time Reached/Hit Condition
Figure 97. Polling for Timestamps of Sync or Delay_Req
B4393-01
Client Application
IEEE 1588 Hardware Assist Block
IxTimeSyncAcc
ixTimeSyncAccSystemTimeSet(systemTime)
ixTimeSyncAccTickRateSet(tickRate)
ixTimeSyncAccPTPPortConfigSet(ptpPort,ptpPortMode)
Set system time
Set frequency scaling factor
Set port mode - Master/Slave
Sync/Delay_Req detected(Sent and/or Received)
Set event flags for sent and/or received system time snapshot
ixTimeSyncAccPTPRxPoll (ptpPort,*ptpMsgData)
ixTimeSyncAccPTPTxPoll(ptpPort,*ptpMsgData)
Get receive snapshot data for Port #n
Get transmit snapshot data for Port #n