2008-03-27 13:04:54     can't change AMGCTL register on startup

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2008-03-27 13:04:54     can't change AMGCTL register on startup

Michiel Verschueren (BELGIUM)

Message: 53158    Hi,

 

I'm using a custom plug-on board for the bf561 ezkit.

I want to access the devices on the board through the asynchronous memory interface. Therefore, I want to change the contents of the AMGCTL register on startup. The reset value of this register is, according to the blackfin's hardware reference, 0x00F2.

 

With my debugger (icebear), I can see that the value after startup is 0x003F. I have deduced that this is the value of CONFIG_EBIU_AMGCTL_VAL, defined in bf561-ezkit.h.

The problem is that, when I change the value of CONFIG_EBIU_AMGCTL_VAL from 0x3F to something else, the value I see after starting up U-Boot still remains 0x3F. I don't see why the register value doesn't change.

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2008-03-27 15:25:07     Re: can't change AMGCTL register on startup

Mike Frysinger (UNITED STATES)

Message: 53164    after changing the config value, you may want to do `make clean` before doing `make` so you know the config changes are used

 

how are you "starting up u-boot" ?  simply loading into memory and doing "go" wont reprogram the clocks.  you'll need to write it into flash and boot it from there.

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2008-03-28 04:57:16     Re: can't change AMGCTL register on startup

Michiel Verschueren (BELGIUM)

Message: 53242    Thanks. This helped.

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