From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <3A9EFA26.8030805@bigpond.com> Date: Fri, 02 Mar 2001 12:40:54 +1100 From: Brendan J Simon Reply-To: brendan.simon@bigpond.com MIME-Version: 1.0 To: linuxppc-embedded Cc: Dan Malek Subject: linuxppc-embedded: mpc8260 bus frequency calculations Content-Type: text/plain; charset=us-ascii; format=flowed Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: I've come accross a problem where our custom embedded 8260 board is losing time. I've tracked it down to the bi_busfreq value being set to 66 instead of the true value of 66.6666666666666666666666666666666666666. One solution is to have the board_info fields in units of Hz instead of MHz. I could then set the bi_busfreq value to 66666667 for much better accuracy. Another solution might be to regularly read the real time clock. Does linux do this normally or does it just read the RTC once at boot up and then just rely on it's internal timers for the system time. I can't see how this can be very accurate. Thanks, Brendan Simon. ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/