RosettaCodeData/Task/Fibonacci-sequence/Z80-Assembly/fibonacci-sequence-1.z80

19 lines
221 B
Z80 Assembly

; 8 bit version
; IN : a = n (n <= 13, otherwise overflows)
; OUT: a = FIB(n)
fib8: cp 2
ret c ; if n < 2 then done
ld b,a
dec b ; b = n - 1
ld c,0 ; F0
ld a,1 ; F1
f8_l: ld d,a
add a,c
ld c,d
djnz f8_l
ret