I am currently trying to indirectly address the SRAM of the ATMega328P by using the following code:

ldi XL, 0b11111111 ;load pointer ldi XH, 0b00001000 ldi r16, 0b01001011 ;load value sts X, r16 ;write value 

However, AVRA detects an error in the given code:

main.asm(51) : Error : Found no label/variable/constant named X 

I don't know, what is wrong with my code because I found similar examples online (http://www.rjhcoding.com/avr-asm-sram.php).