Re: [avr-gcc-list] Mega48 EEPROM problem?

[Bob Paddock]

Answering my own question.

For the Mega48 the logic at the end of
<avr/io.h> is flawed because iomx8.h sets E2END to 0xFF.

#if E2END < 0x100 && !defined(__COMPILING_AVR_LIBC__)
# undef EEAR
# if E2END > 0
#   define EEAR _SFR_IO8(0x1E)
# endif
# undef EEARH
#endif


On Wed, 30 Mar 2005 13:55:44 -0500, Bob Paddock  
<address@hidden> wrote:

> I am trying to use the EEPROM of the Mega48 with latest WinAVR (3.4.3).
> A full test case is at the end of this message.
>
> What I do not understand is how this:
>
>      /* Set up address and Data Registers */
>      EEAR = 0x0010;
>
> translates into this:
>
> .LM6:
>    42 0012 80E1                 ldi r24,lo8(16)
>    43 0014 8EBB                 out 62-0x20,r24
>
> According to my math 62-0x20 equals 0x1E, which is wrong for the Mega48.
>
> It seems that these defines are not being used, and I'm not sure
> what defines are being used?