Zilog Z08470 User Manual
Page 42
Hardware and Software Implementation
UM008007-0715
30
Z80 CPU
User Manual
19
;
l
unused
20
;
ix
pointer into data array
21
;
iy
unused
22
;
0000
222600
23
sort:
ld
(data), hl
; save data address
0003
cb84
24
loop:
res
flag, h
; initialize exchange flag
0005
41
25
ld
b, c
; initialize length counter
0006
05
26
dec
b
; adjust for testing
0007
dd2a260
0
27
ld
ix, (data)
; initialize array pointer
000b
dd7e00
28
next:
ld
a, (ix)
; first element in comparison
000e
57
29
ld
d, a
; temporary storage for element
goof
dd5e01
30
ld
e, (ix+1)
; second element in comparison
0012
93
31
sub
e
; comparison first to second
0013
3008
32
jr
pc, noex–$
; if first > second, no jump
0015
dd7300
33
ld
(ix), e
; exchange array elements
0018
dd7201
34
ld
(ix+i), d
001b
cbc4
35
set
flag, h
; record exchange occurred
0010
dd23
36
noex:
inc
ix
; point to next data element
001f
10ea
37
djnz
next–$
; count number of comparisons
38
; repeat if more data pairs
0021
cb44
39
bit
flag, h
; determine if exchange occurred
0023
20de
40
jr
nz, loop–$
; continue if data unsorted
0025
c9
41
ret
; otherwise, exit
42
;
0026
43
flag:
equ
0
; designation of flag bit
0026
44
data:
defs
2
; storage for data address
45
end
Table 2. Bubble Listing (Continued)
Location
Object
Code
Statement
Source Statement