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[ECOS] MBX hal clock settings
- To: ecos-discuss@sourceware.cygnus.com
- Subject: [ECOS] MBX hal clock settings
- From: Jamie Guinan <guinan@bluebutton.com>
- Date: Mon, 26 Jul 1999 16:06:56 -0400 (EDT)
- Reply-To: guinan@bluebutton.com
Hi,
I was studying the MPC823 clocks, and I noticed what
appears to be a small error.
In packages/hal/powerpc/mbx/v1_2_3/src/mbx.S, the setting
for the PLPRCR register at 50MHz uses 0x5fa in the MF
(multiplication factor) field. Doing the math, I get,
50*1000*1000 / 0x5fa = 32,786
The crystal is suppoed to be 32,768 (not 86), so I belive
the appropriate value should be 0x5f5.
50*1000*1000 / 0x5f5 = 32,768
There is actually some remainder there, but with 0x5f5
the frequency is low by 28.8Khz versus over by 135KHz
with 0x5fa (assuming the crystal is accurate).
(I didn't consider this a "support issue" so I just posted
here - let me know if there is a better place to report
bugs like this).
-Jamie
================================================================
Jamie Guinan Blue Button Solutions, Inc.
guinan@bluebutton.com http://www.bluebutton.com
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