mov r1,0     // sometimes, xor r1,r1 needs less program space and/or time
    mov r2,N
loop:
    // do something with r1
    inc r1       // may or may not set flags, depending on the implementation
    cmp r1,r2    // often imlemented as sub r1,r2 but without actually writing the result back to the register, just setting flags
    jne loop     // if implemented as sub r1,r2, jne (jump if not rqual) is equal to jnz (jump if not zero)