ZiLOG Z80 User Manual page 58

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16
17
0000 0610 18
0002 4a 19
0003 7b 20
0004 eb 21
0005 210000 22
0008 cb39 23
000a if 24
25
000b 3001 26
good 19 27
28
000e eb 29
goof 29 30
0010 eb 31
0011 10f5 32
0013 c9 33
34
; a low order bits of multiplier
;
ld b, 16;
ld c, d;
ld a, e;
ex de, hl;
ld hl, 0;
mloop: srl c;
rra
;
jr nc, noadd-$; if no carry, skip the add.
add hl, de;
;
noadd: ex de, h l;
add hl, hl;
ex de, hl;
djnz mloop-$;
ret;
end;
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number of bits-initialize
move multiplier
move multiplicand
clear partial result
shift multiplier right
least significant bit is
in carry.
else add multiplicand to
partial result.
shift multiplicand left
by multiplying it by two.
repeat until no more bits.