Zilog Z08470 Manual de usuario descargar pdf (Pagina 42)

Hardware and Software Implementation UM008007-0715

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

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

1 2 ... 37 38 39 40 41 42 43 44 45 46 47 ... 325 326

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Zilog Z08470 Manual de usuario Pagina 42