RE: RE: clock speed of mpc565

Randy is usually spot on, but in this case I just can't see why he's
recommending div 2 and x 28 - seems your div 1 and x 14 would work also.
Perhaps I'm missing something obvious.  
 
If you can't get your hands on an oscilloscope or frequency meter, its
going to be kind of difficult for you to debug a PLL.  Intronix do a
Logiport 34 channel logic analyser for around $300 which works off a PC
and a USB port - this is a great little tool that does a lot more than
just measuring frequency on CLKOUT.  It also has an SCI decoder.
 
- Allan

________________________________

From: [email protected] [mailto:[email protected]] On Behalf
Of maboulais
Sent: Monday, June 25, 2007 3:57 PM
To: [email protected]
Subject: [MPC500] RE: clock speed of mpc565




Hi,
I was wondering if there was techical documentation on this. I am using
an
MPC566 and was assuming that I could just set fields MF = 13 and DIVF =
0 in
the PLPRCR register with a 4 Mhz oscillator clock. 

Fsys = 56 Mhz = ( 4 Mhz / (DIVF + 1) ) * ((MF + 1) / ((2^DNFH) or
(2^DNFL
+1))

where DNFH = 0, DNFL = 0

I don't have a logic analyzer so it's hard for me to validate this. 

Dees Randy-rsaf30 wrote:
> 
> 1. if using a 4 MHz crystal, you must set the predivider to divide by
2
> (to get 2Mhz into the PLL), then set the multiplier to 28 to a 56 MHz
> system clock.
> 2. programmable to same as the system frequency or system frequency
> divide by 2.
> 3. it depends on the frequency you select. the bit rate is
programmable.
> 
> randy. 
> 
> ________________________________
> 
> From: [email protected] <mailto:MPC500%40yahoogroups.com>
[mailto:[email protected] <mailto:MPC500%40yahoogroups.com> ] On
Behalf
> Of huzaec
> Sent: Tuesday, April 10, 2007 1:13 AM
> To: [email protected] <mailto:MPC500%40yahoogroups.com> 
> Subject: [MPC500] clock speed of mpc565
> 
> 
> 
> i have few more questions regarding clock speed of mpc565..
> 
> 1. How is it possible to maximize the clock speed to 56MHz through 
> programming??
> 2. What is the bus speed of in mpc565??
> 3. At what speed does the UARTs operate ?
> 
> 
> .
> 
>
<http://geo.yahoo.com/serv?s=97359714/grpId=6276387/grpspId=1706554205/m
<http://geo.yahoo.com/serv?s=97359714/grpId=6276387/grpspId=1706554205/m
> 
> sgId=3849/stime=1176185590/nc1=3848614/nc2=4507179/nc3=4025304> 
> 
> 
> 
> [Non-text portions of this message have been removed]
> 
> 
> 

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