Please include full working code, Including any setup code. I have what i think should work, but i keep getting errors

for 8.1 I have,

LDI r16, 0xFF

OUT DDRA, r16

LDI r16, 0x53

OUT PORTA, r16

I get the errors 'Undefined symbol:DDRA' and Undefined symbol: PORTA'

For 8.2 I have

LDI r16, 0x00

OUT DDRB, r16

IN r20, PINB

With similar errors, I dont know how to 'define' the ports and DDRB/DDRA

The code needs to actually work in the Atmel assembly studio

E8.1 Write an instruction sequence to output the value 0x53 to PORTA. E8.2 Write an instruction sequence to read the value in register r20. voltage levels on PORTB pins and place the E8.1 Write an instruction sequence to output the value 0x53 to PORTA. E8.2 Write an instruction sequence to read the value in register r20. voltage levels on PORTB pins and place the