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Altera_Forum
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16 years ago

uCLinux NIOSII LCD 16207 problem

Hi all, I'm very new uClinux user. I'm playing with an Altera DE2 kit, trying to make working an example found in the NIOSWIKI (http://www.nioswiki.com/operatingsystems/uclinux/lcd_16207...
Altera_Forum's avatar
Altera_Forum
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15 years ago

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If the address bit 31 is set, NIOS disables the cache for that access. This is necessary for I/O accesses. This only works for the non-MMU version of NIOS.

OTHO AFAIK, there are arch independent macros defined in the Linux header files that can be used to define I/O addresses in a hardware-independent way.

-Michael

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so it is decided by non-MMU version of NIOS II,when you set the address bit 31 to 1,there is no cache.Maybe I know it now! Thank you very much!