PTP on blackfin

Hello:

I am looking for info on running PTP on Blackfin Linux. I have read  the wiki page http://docs.blackfin.uclinux.org/doku.php?id=uclinux-dist:ptp as  well as the BF518 HRM chapter 23 on IEEE 1588 PTP ENGINE. My  understanding is that ptpd will "automagically" adjust the hardware  clocks between two BF518 boards, one being master and one being slave.  The precision of this adjustment is 12.5 ns claimed in the BF518 Data  Sheet.

Questions:

1. The daemon ptpd can also run on other Blackfin chips. What is the  precision achieved with ptpd on Blackfins other than BF518?

2. Is there any info available (App Notes, articles) showing the  actual performance achieved on either BF518 or other Blackfins?

3. Are there any reference designs or examples available showing the  usage of the pulse-per-second PPS output?

4. Is the PPS output available from chips other than BF518?

Thank you -- Wojtek

  • 1, this is the PTP on software, we don't test it

    2, you can test it in your environment, here is how I do the test and my result:

    On the master board
    root:/> date -s 2010.03.16-15:30
    root:/> ptpd -z linux_hw -f log.master
    On the slave board
    root:/> date
    Tue Jun 5 05:07:07 UTC 2035
    root:/> ptpd -z linux_hw -g -f log.slave
    root:/> date
    Tue Mar 16 15:32:37 UTC 2010
    cat log.slave
    (ptpd debug) master-to-slave delay: 0s 44483ns
    (ptpd debug) slave-to-master delay: 0s 56536ns
    (ptpd debug) one-way delay: 0s 39828ns
    (ptpd debug) offset from master: 0s 4900ns

    4, it's part of the IEEE1588 engine module so no for other chips without this module.