[ECOS] Altera EPXA1 Excalibur: changing the clock output of PLL1

[Stephan Bourduas <stephan at macs dot ece dot mcgill dot ca>]

I'm trying to get dynamically reconfigure PLL1 on my EPXA1 board via the 
procedure outlined in an177.pdf from the altera website.  When I change the 
clock output of PLL1, my serial output doesn't work anymore, but when I 
change back to the default value, the serial port works propely.  

I think that I somehow have to re-initialize the serial port to use the new 
clock speed.  Does anyone know how to do this?

Stephan

PS:  below is a related email I found searching the lists:


> ecos-discuss Digest of: thread.27071
> 
> 
> Excalibur AHB1 clock change
> ????????27071 by: "J Jordaan" <jjordaan@sun.ac.za>
> 
> From: 
> "J Jordaan" <jjordaan@sun.ac.za>
> 
> 
> To: 
> <ecos-discuss@sources.redhat.com>
> 
> 
> Date: 
> 21/05/04 07:34 am
> 
> Hi All
> 
> I've been trying to change the AHB1 clock of the Altera Excalibur Epxa1
> board without any success. According to the datasheets you can change it in
> a user application by first bypassing the PLL1. You do this by setting the
> BP1 bit in the CLK_DERIVE register. I do this with the following commands :
> 
> 
> 
> cyg_uint32 reg;
> 
> HAL_READ_UINT32(EPXA1_CLK_BASE + _CLK_DERIVE, reg);
> reg |= 0x1000;
> HAL_WRITE_UINT32(EPXA1_CLK_BASE + _CLK_DERIVE, reg);
> 
> 
> 
> The moment I do this the whole system just hangs. When a bypass the PLL2
> with the same commands, it works without a problem.
> 
> Does anybody know what the problem could be or what I'm doing wrong?
> 
> Thanks
> Jacques

--
Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos
and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss