[Icc-avr] Reading fuses on Mega168

[Magnus Johansson]

> whereas the second example uses in instruction to load 0x37 into R16 and 
> clrs R17.

Well, what Johan said, whatever byte is at address 0x37.

> The actual definition of SPMSCR is
> 
> #define SPMCSR    (*(volatile unsigned char *)0x57)
> 
> which for some strange reason the compiler translates to 0x37.

Check out the m48/m88/m168 datasheet pages 345 and 346, especially the 
notes on page 346.