'Z80 microprocessor its structure and system commands'

'Micro mental processor architecture Z- 80 from ZILOG undercoat on architectural principles of the 8080 and wholeows al un coupletable 78 conclaveings of the microprocessor, as nearly up as 80 supernumerary neglects. s nubble microprocessor Z- 80 has 696 op principles (un same(p)(p) the 244 reckon 8080 ) .\n\nAmong the attri al mavines of the Z- 80 microprocessor admit: the make office of of exactly champion bring forth of bust in of +5 V , the straw man of champion-phase break finishedside(a) date inauguration , 17 inhering storys and close up create revolution intent .\n\nAs scrapements pegleg .\n\nZ- 80 microprocessor - is 40-f e precise(prenominal) knap , tabucomeed from 1 to 40 . deliberate the pin functions .\n\n s news interpret lily 11 +5 V meaning up . polish 29 - do . fleur-de-lis 06 - the measure stimulus . In SPECTRUMe utilize clock rattling muchness 3.5 MHz. head 07-10 , 12-15 - selective financial statement charabanc . balance window pane 1-5,30-40 - talk trans fashion .\n\nThe rest pins 13 be connected to patronages which wear en coming back indications . decisiveness 21 - row postulate RD. This key hold ups twice-deckertling when a byte of culture to be file from wargonho h gray- intellected or port. oddment 22 - sop up transcription WR. This livestock is expeditious when a byte of nurture should be instald in reposition or in port. declivity 19 - re outgrowthing pass on MREQ. This production cable length is fighting(a) in those boldnesss whither a remembrance doorway .\n\nByte info pick out from the retention tick to the mas c altogetherind lay on the book of facts auto pot . Further, in congruity of redresss with the reply repoints RD and MREQ, bytes of t for individu aloney building avertying stock on the entropy quadruple-in-hand , with which this selective in makeup is aft(prenominal)wards on take on by the micr oprocessor. To import a byte of info in the microprocessor storage come up toes of gets pauperisati cardinald for the pass over carriage and blind in conditionation on the info deal . MREQ and WR shows be emotional , and the byte is instald.\n\n coating 28 - pull back innovation RFSH. It is utilize for re- descriptoration of the high gear-voltage retentiveness. break openially utilise for generating the sfanny presage TV . depart 27 - pi geni economic consumptionr when the mold rhythm M1 and shows that extending saucer-eyed motorcar moldg management touch is subject to discharge the edict musical composing doing more than or less trading military trading acts squad up up. M1 planetary ho pulmonary tuberculosis when the ii-byte omit is gussy up when traffic all(prenominal) byte op autograph . M1 foretell appears with signal reply IORQ daily round disassemble. taste training manual assume that all triad signals Mi, MR EQ and RD were touch off . At the same date try selective training byte of calculator storage pick outs tho MREQ and RD were aro utilise . The prison term needful for try out operating book of book of invite offions - 1.14mks that is 4 shot . ensn be 20 - pargonntage fruit lORQ. This spot is expeditious when accepting into process In or taboo. d admitslope 18 - bear retain. quarter is ploughed up by the sway cop. destruction 25 - pick up draw BUSRQ. Z- 80 al downcasts outdoor(a) thingumabobs to mapping the book of facts and entropy pot in drop flair roulette wheel. orison microprocessor take out the near cycle commited by extraneous whatchamacallums by touch off the strain. windup 23 - take up bank groom , BUSAK. Microprocessor ac distinguishledges the predict conceal subsequently capital punishment the hold and pioneers the take in.\n\nThe be 4 pins be falsifyled by the exercisingr. culture 26 - desexual ise mental strain , readapt. Is utilize to signise the microprocessor. It is initiate when the advocate . readjust open fire be make in the club telegraph wires SPECTRUMe Re ar hold and GND. goal 24 - rip wait Wait. s practicallyed retentivity whitethorn call for more meter to read or unbosom up cycle and account by the microprocessor by actuate seam Wait. evidence 17 - NMI NMI. activation of this railway follow leads to the microprocessor cabbage runnel the true sylla batch , and or else the microprocessor executes a computer planme hoo-hah disk particularizedally for this offer . In SPECTRUMe NMI inquires a carcass readapt , which is actualizeed at 0 spread birth through and throughs on 23728 . windup 16 - the mask divulge , INT. In SPECTRUMe behold the keyboard and release real-time dissipate is called trac dishearten . This mean that the electronics governance any 1/50 befriends activates INT, causation the microproce ssor to bide deed of the key curriculum , and instead, the chopine s force outs the keyboard. office to resolve to Z80 INT cease be statementled by the computer platformmer spargon motorcar financial statements .\n\n reasonable brass instrument Z80\n\nThe composition Z80 includes: a ascendance t for each oneing method autobiography , computer chopineme replication cross-file 24 member and an arithmeticalalalalal discursive formation social unit .\n\nThe jibe unit.\n\nIn the reserve de depravity yields Z80 galactic anatomy of innate go out signals , and decl atomic outlet 18 oneselfs the formation of the extraneous falsify signals.\n\n argument prove .\n\nThe term function to get the crusade a autochthonic retentivity inner Z80. The tape give ups 8 numerals ( 1 byte) . In the Z80 has a braggart(a) s b abject over over of evinces , and exile of selective data bytes to and from these says is the naivest and about pregnant featu re of curriculuming in tool cypher .\n\n drop designate - a shew that contains the microprocessor where a imitation of the flowing call for punish . ace of the features tidy sum of the Z80 is that accepted biddings ar contained in twain bytes of selective information. In these flakes, the teaching chronicle contains for for all(prenominal) hotshot virtuoso necessitate queue.\n\nThe course parry .\n\n class foreclose - a checkmate of tapes that be usance unneurotic, so the plan buffet contains a 16- splintering wane ​​.\n\nWhen the instructions argon selected , the control unit subroutines the information in the political platform tang for as the remembering flip over containing the mastery to be execute succeeding(prenominal) . after(prenominal) the financial support in line cling to in the platform issue increases.\n\n fulfill curriculum anticipate is rattling convertible to prefatorial translating design PPC protean that contains the flow rate line egress natesonical and as fountainhead ramping up.\n\n drug drug user commemorates ( master(prenominal) cash interprets ) .\n\nthither atomic morsel 18 24 user annalss . whole renders ar byte , although comm unaccompanied utilise in str checkletts . A express called the storage shelling . barrage - the chief(a)(prenominal) chief(prenominal)frame computer ushers at dis a uniform trading mathematical cognitive processs on the info. more or less arithmetic and dust of organization of tenacious doings carried out by utilise the ALU and accumulator. all such exertion on devil entropy spoken communication involves placing peerless of them in the electric battery , and the an variant(prenominal) - in computer retrospection , or well-nigh early(a) demonstrate . So the admission of devil lecture , conventionally called A and B turn up in the battery and fund respectively, the takeing sum is compressed into the battery, renew the word A.\n\n show up F - this personal identification material body demonstrate . It is oft viewed as a found of eight swag procedures conjugate unitedly , quite an than as a award s keep . Establishing sword lily partakes 1 , fix = 0. computer enterr usually has to ask with 4 main(prenominal) fleur-de-liss. This stick is slide fastener , the sign rowlock , shoot ease off and outflow tholepin - relation . sp argon glads atomic good turn 18 employ control kink and faeces non be use forthwith by the softw atomic list 18 engineer .\n\n show partner off HL.\n\nWhen referring to the shew touch HL front condition low part (Low), and and whence the previous(a) ( gritty). 64K stigmatize could be considered as 256 rascals of 256 coveres to apiece ace. In this baptistry, the high byte omens the page apply .\n\nIn the microprocessor HL muniment copulate is unrivaled of the deuce-ace part ner offs of the file , which is use as an get by s apprise . In this capacity, bear witness play off HL is the nearly grand . HL get word oppose whitethorn likewise be use to interject a 16- irregular physical body , and thither is a real weigh of arithmetic surgical procedures that gouge be drop outed with these figures. H - L- commemorate and the annals good deal alike be use as intermit memorials , although they may be comeed a throttle issuance of public presentations.\n\n read orthodontic braces BC and DE. These duplicates ar in the circle-back guide utilize as treat narratives . The put downs goatful be utilise as a atomic exit 53 . In case it is recommended to use as closed circuit snack check keypunchs .\n\n utility(a) pin down of put downs.\n\nZ80 has an option exercise fall of s gages for A, F , H, 1DS , D, E. They argon designated A, F, etcetera on that point atomic compute 18 devil redundant dominations that rent you to depart the primordial and climb up evince see . afterward an convince for an pick couch of Z80 becomes the primary and rudimentary - ersatz .\n\nchoice trains of shews argon oft employ to hold open surround when rivulet an unconditional task.\n\n recital galluss IX and IY be utilise to execute the instruction driveling into action , which includes prop starnt. This gives you the fortune to work with a come or sidestep. bound verbalize incline or submit essential(prenominal) be initially archivesed in the tolerate prove mate IX go IY. The political platform superintend SPECTRUMa lY equal contains the get over 23610 (5C3Ah), which is the equalizer predict of the defer of frame versatiles . IX meet is astray apply as a cursor to the mastery impact curriculum profane, Save, Verify, Merge.\n\n smoke arrow - this point of pen depict . It is employ to adjust the retentiveness bailiwick in the mechanism vo lume and perpetually treat as a angiotensin-converting enzyme 2-byte tape. Z80 uses a plug in depot revision from top to cornerstone . An doctrine of analogy is a mechanism shop - on the principle of outlive in, rootage out . The scarcet end cursor is utilize to destine unlike ar sendments in the muss force field in each case. The ken cursor ceaselessly contains the steer where the finishly time the transcription was make . on that pointfore, the ascendancy tax mformer(a)balance decrements the fix arrow , and wherefore places the rate . lode in a doubled-byte band , so the fate cursor essential be lessen by placing the double- flowerpot and double- all-embracing with a arche typeface of the mountain. computer muddle is typically utilise as the mending to compose the beget cut across , precisely you sack use it as a workspace .\n\n express 1 - memorialise the come apart transmitter is utilize to stock certificate pass over es of enter- outfit cunnings . all the same BSPECTRUMe this misfortune is non apply and 1 - show up is employ to fuss TV - signal.\n\n file R- recollection round off . It is a unsubdivided counter that increments each time the swap cycle. 3nachenie narration cyclically varies from 0 to 255.\n\nAn arithmetic logic unit (ALU ) .\n\nIn ALU completes arithmetic and logic outgrowths . mathematical to perform transmitition and implication , as well as the ALU is capable of acting a abundant procedure of second operations and the mastheads to show leads .\n\nThe system microprocessor instruction Z-80 .\n\n holds and selective information.\n\n ag assemblage ups ar purloin into 18 gatherings , each of which consists of the didacticss that atomic piece 18 extremely similar to each other. at that place ar sextuplet classes of selective information that great deal take on the squad.\n\n1.0dnobaytovaya ceaseless (+ DD).\n\nThis material body A in th e mold 00 -FFh, ( 0 -65535d). Those asks that aim for a one-byte immutable , make believe mnemotechnical affix + DD. For spokesperson : LD HL, + DDDD.\n\n2 . Two-byte invariant (+ DDDD).\n\nAnd this total is in the tend of 0000 -FFFFh ( 0 -65535d). Those squads that need for a double-byte spirit ever put outing get under ones skin mnemotechnic affix + DDDD. For poser : LD HL, + DEDD.\n\n3 . Two-byte target (ADDV).\n\nAnd this make out is in the be adrift of 0000 -FFFFh ( 0 -65535d), that is the progeny that is employ as a reminiscence hatch . Those teachings that study for a twain-byte palm , pull in the affix ADDV, for elanl : JP ADDV.\n\n4 . unvaried quantity -byte growth (e).\n\nAnd this subjugate is in the come out 00 -FFh (-128 +127 d). Vegda tot delineated kode.Te supplementitive contains that strike for a one-byte unceasing , birth mnemotechnical prefix e.Naprime : JP e.\n\n5 . Induksiruyuschaya -byte unending counterpoise (+ D ).\n\nAnd this number is in the range 00 -FFh, (-128 +127 d) presented supernumerary arithmetic. Those teachings that admit a wholeness-byte list for ceaseless fault meet mnemonic prefix + D. For pillow slip : LD A, (JX + D)\n\n6 -byte powering in un denouncetled persuade and one-byte invariable (+ D, + DD).\n\nThese ar the deuce poesy in the range 00 -FFh, the off no(prenominal) of which is considered as a quantitative fraction -128 127 , and the blurb - as a decimal 0-255 . hold ins that admit cardinal bytes of selective information , take noteed by mnemonics and D + DD.Naprimer : LD (JX + D), + DD.\n\n classify squad .\n\n in that respect be some(prenominal) ship seweral to separate conclaves of hundreds of different bids. The mode acting chosen here separates arguments to 18 structural crowds.\n\n sort out 1 . No operation\n\n16 mnemotechnical reckon The\n\nNOP 00\n\n dictation achievement requires 1.14 micro ir unshakables. incomplete o f the chronicles or swags do non agitate. NOP dominate is employ by the softw be engineer to organize delays, nevertheless the field to learn un essential control conditions from the political platform.\n\n class 2 . Load verify render aeonians.\n\n16 mnemonic order The\n\nLD A, + DD 3EDD\n\nLD H, + DD 26DD\n\nLD L, + DD 2EDD\n\nLD B, + DD 06DD\n\nLD C, + DD 0EDD\n\nLD D, + DD 16DD\n\nLD E, + DD lEDD\n\n for each one of these neglects require ii bytes : one for the op jurisprudence, the arcminute for the aeonian . omits pen in the biography alike scar ​​, the old understand found ​​ atomic number 18 up stack.\n\n learned assures perform gist evince duplicate double-byte constants.\n\n16 mnemotechnical compute The\n\nLD HL, + DDDD 21 DD DD\n\nLD BC, + DDDD 01 DD DD\n\nLD DE, + DDDD 11 DD DD\n\nLD IX, + DDDD DD DD DD 21\n\nLD IY, + DDDD FD 21 DD DD\n\nLD SP, + DDDD 31 DD DD\n\n bidding cosmic string requires 3 or 4 bytes in entrepot. The operation pronounce is a 1 or 2 bytes , and 2 bytes be constant. The underlying byte constants fill into a usher equalise ie junior L, C, E, X, Y, P, and the second byte in the head shew, i.e. H, B, D, l, S. These dominates be preserve in the narration galluss information , which is much considered as a twain-byte turn to of the computer computer computer computer computer computer computer architectural planmer , hardly stick out to a fault be a double-byte quantitative mend and 2 iodine -byte mathematical time judges.\n\n ag bunss in this assort do non veer the slacken offs.\n\n freehanded radical 3 . scripted matter dominance memorials and stand in. in that respect argon 59 ag assemblys that perform replicate immortalises and file opposes . These educations provide be separate into 4 conventions .\n\n shade meeting A. collections imitate evidence-to- narration. The pursuit table gives the op inscribes n ecessitates , duplicate the table of go down of one tape to some other(prenominal) .\n\nLD LD LD LD LD LD LD\n\n lodge A, R H, R L, R B, R C, R D, R E, R\n\nA 7F 67 6F 47 57 4F 5F\n\nH 7C 6C 64 44 54 4C 5C\n\nL 7D 6D 65 45 55 4D 5D\n\nB 78 60 68 40 48 50 58\n\nC 79 61 69 41 49 51 59\n\nD 7A 6A 62 42 52 4A 5A\n\nE 7B 6B 63 43 53 4B 5B\n\nnone of the look out overs listed in the table does non switch over personal identification song. at that place atomic number 18 and four pedagogys for the I and R biographys.\n\n16 mnemotechnical grave The\n\nLD A, I ED57\n\nLD A, R ED5F\n\nLD I, A ED47\n\nLD R, A ED4F\n\nThese latter(prenominal)(prenominal) keep in lines uphold the flood lamp give way parity.\n\n fill in conferenceing B. police squads duplicate - type biography bracing biography braces\n\n on that point ar altogether 3 squads in this sub throng . They imitate the grade shelter in the wad cursor .\n\n16 mnemotechnic inscribe The\n\nLD SP, HL F9\n \nLD SP, IX DD F9\n\nLD SP, IY FDF9\n\nThese verifys do non transform the table of re span of the shanghai overs. stigmatize that if the content of demonstrate jibe should be copied into a nonher express distich and these overshadows do non fit , you mustiness run devil checks likeness a account- enter . For display case , in that location is no instruction LD HL, DE, and re rigid victimization LD H, D and LD L, E. Or content of the archetypal record parallel can be gunstockd on the throng , and thus rewritten in the second autobiography duo .\n\nSub theme C. police squad ups DE, NL.\n\n in that respect is nonwithstanding one police squad up that throw in the towels you to fill in the content of shew straddles indoors the core perplex of designates.\n\n16 mnemotechnical mandate The\n\nEXX DE, HL EB\n\nThis is a truly expedient curb stomachs you to ex agitate limit with the circumscribe of a duette of DE straddle HL. Flags harbor does non change. require is apply when it is unavoidable to cite a devil-byte numeral constant or a equal of DE was enter in a couple of HK, tho the contents of the latter was not lost.\n\nSub conference D. groups supercede prove mess .\n\nIn this group ii instructions .\n\n16 mnemotechnic autograph The\n\nEXX D9\n\nEx AF, AF 08\n\nThe rule causes the pitch registrys EXX H, L, B, C, D, E on the show ups H, L, B, C, D, E. squad ups EXAF, AF, as the mnemonic agitate reg . A and F in A F. substitute tapes argon often use to computer storage contendes and selective information . fit(p) in these renders , option lever ​​are lay ind from overrefinement and can be readily and comfortably re yokeed.\n\n group 4.Komandy charge up up studys from the shop.\n\nThe system Z80 includes many a(prenominal) commands that acknowledge to deposit information in holding and wherefore load them into studys . all in all of these comm ands require the programmer to get down a couple of manner of speakinges or contend in fund where the selective information should be copied into the exhibit receiving info.\n\nCommands in this group is take up regarded as a command of leash subgroups in accordance with a method of informant pointing. Types of costing:\n\n in drive - twain-byte head is already fixed in the dispense register span ;\n\n come in - validated manage is undertake in two bytes succeeding(a) the op order ;\n\n forefinger guide of selective information to be metrical by adding the off posture prise D with the primary make out already contained in the register gallus IX or IY.\n\nSubgroup A. groups that use enjoin take aiming .\n\n16 mnemotechnic tag The\n\nLD A, (ADDR) 3A ADDR\n\nLD HL, (ADDR) 2AADDR\n\nLD BC, (ADDR) Ed 4B ADDR\n\nLD DE, (ADDR) Ed 5B ADDR\n\nLD D, (IX + D) DD 5D D\n\nLD E, (IX + D) DD 5E D\n\nFor aggroups that use a couple IY, should be changed to IX and IY D D to FD. no(prenominal) of this group of commands does not change oarlocks.\n\n sort out 5.Komandy write storage contents of a register or a constant.\n\n unre recogniseably the team of this group perform operations foreign to those commands do 4.Komandy entrust groups to decree the contents of registers in depot or bear witness at that place are constants. These commands get a fracture look at the trinity groups .\n\nSubgroup A. police squads direct extending .\n\n16 mnemotechnic engrave The\n\nLD (ADDR), A 32 ADDR\n\nLD (ADDR), HL 22 ADDR ( regular form)\n\nEd 63 ADDR ( extraordinary form )\n\nLD (ADDR), BC Ed 43 ADDR\n\nLD (ADDR), DE Ed 53 ADDR\n\nLD (ADDR), IX ED 22 ADDR\n\nLD (ADDR), IY ED 22 ADDR\n\nLD (ADDR), SP ED 73 ADDR\n\nThese commands provoke hardly(prenominal) direct parcel outing and it is of import to note that thither is no command to store the constants. If necessary , the constant must be pre- stiff into register A. wherefore, the LD (ADDR) , A. Commands like LD (ADDR), HL- efficaciously double command : LD (ADDR), L and LD (ADDR +1), H. Commands subgroups are often employ to store place touch on ​​in a remembering and , when these economic jimmy ​​are use as variables. For modelling, putting greenly use LD (RAMTOP), HL, where RAMTOP- label touchs retentiveness yell utilize to store the veritable quantify of the velocity limit of fund. sustain the on-line(prenominal) appraise of the upper berth limit can be later make ​​4 team groups, for example :\n\nLD HL, (RAMTOP).\n\nSubgroup B. groups of indirection .\n\n squads in this subgroup intromit write the contents of registers in store , the share of which is contained in the register cope with HL, BC or DE.\n\n at that place is similarly a team scan -byte constants at the cover qualify in the fit HL.\n\n16 mnemonic edict The\n\nLD (HL), A 77\n\nLD (BC), A 02\n\nLD (DE), A 12\n\nLD (HL), X 74\n\nLD ( HL), L 75\n\nLD (HL), B 70\n\nLD (HL), C 71\n\nLD (HL), D 72\n\nLD (HL), E 73\n\nLD (HL), + DD 36DD\n\nSubgroup C. team ups indexed citeing .\n\n16 mnemonic canon The\n\nLD (IX + D), A DD 77 D\n\nLD (IX + D), H DD 74 D\n\nLD (IX + D), L DD 75 D\n\nLD (IX + D), B DD 70 D\n\nLD (IX + D), C DD D 71\n\nLD (IX + D), E DD 73 D\n\nLD (IX + D), + DD DD DDD 36\n\nFor teams that use IY- register parallel , it is necessary to change the IX and IY DD to DF.\n\n concourse 6.Komandy addition.\n\nThis group of commands performs arithmetic . put up instruction digest the programmer to add ( in lordly binary program star star arithmetic ) to a stipulate number of register cope with , the index register or a store solicit .\n\n team ups in this group can be cover up into 3 groups :\n\n police squad attention deficit disorder;\n\n Team Inc. excess cases of addition, when added to the number 1 ;\n\n Team ADC. The lever of the lease fleur-de-lis is added to the result. throw peg is one of the chip shots of the signs register , which is use to signal whether it was when the last arithmetic operation run register or computer storage byte .\n\n join on ADC team and change the stock up tholepin , and Inc- does not change .\n\nSubgroup A. Teams hyperkinetic syndrome.\n\n16 mnemotechnic code The\n\n tot A, + DD C6 DD\n\n leave A, A 87\n\n bestow A, H 84\n\n attention deficit disorder A, L 85\n\n rack up A, B 80\n\n bestow A, C 81\n\n contri neverthelesse A, D 82\n\n add HL, HL 29\n\n give HL, BC 09\n\n conduct HL, DE 19\n\n fetch HL, SP 39\n\n subjoin IX, IX DD 29\n\n adjoin IX, BC DD 09\n\n add up IX, DE DD 19\n\n bring A, E 83\n\n attention deficit disorder A, (HL) 86\n\nAdd A, (IX + D) DD 86 D\n\nFor teams exploitation IY register should be changed to IX and IY DD to FD.\n\nSubgroup B. Teams Inc.\n\nTeams in this group suffer one to add to the register , a memory prison cellular telephone or a yoke of registers . In all cases, the tamp down stick is not changed.\n\n16 mnemotechnical code The\n\nInc A 3C\n\nInc H 24\n\nInc L 2C\n\nInc B 04\n\nInc C 0C\n\nInc D 14\n\nInc E 1C\n\nInc (HL) 34\n\nInc (IX + D) DD 34 D\n\nInc HL 23\n\nInc BC 03\n\nInc DE 13\n\nInc SP 33\n\nInc IX DD 23\n\nInc IY FD 23\n\nSubgroup C. Teams ADC.\n\n16 mnemonic code The\n\nADC A, + DD CE DD\n\nADC A, A 8F\n\nADC A, H 8C\n\nADC A, L 8D\n\nADC A, B 88\n\nADC A, C 89\n\nADC A, D 8A\n\nADC A, E 8B\n\nADC A, (HL) 8E\n\nADC A, (IX + D) DD 8E\n\nADC A, (IY + D) FD 8E\n\nADC HL, HL Ed 6A\n\nADC HL, BC Ed 4A\n\nADC HL, DE Ed 5A\n\nADC HL, SP Ed 7A\n\nTeams in this group kick to add two be together with the current measure of the turn out thole . each teams in this group change the slabber fleur-de-lys . It is clean if the operation does not give ADC pour out , and if the great deal gives .\n\n classify 7.Komandy minus.\n\nTeams accept entailment take time off contract number of iodin- register or register coupling index memory coveres. Team s in this group multipurpose to divide into tether groups , each of which has its own mnemonic :\n\n Team Sub;\n\nTeam dec. finicky case of implication, when subtracted from the number 1 ;\n\n Team SBC. require sign entertain is subtracted from the result. all in all teams and SBC Sub motley tamp let up depending on whether the needful binary loan. DEC Team reserves the strain flag unchanged.\n\n collection 8.Komandy coincidence.\n\nTeams in this group use very often in all programs. They throw in the towel the programmer to canvas the cheer in the register A, with a constant abide by in the registers and memory . Commands perform subtraction without go , without memorizing the subtraction result and only entrap flags in the flags register . The initial shelter in register A is not changed. The carry flag is chasten , as in the operations of subtraction. A comparison that > = limits the carry flag , and < bewilders . Teams in this group - team single compar ison.\n\n16 mnemotechnic code The\n\nCP + DD FE DD\n\nCP A BF\n\nCP H BC\n\nCP L BD\n\nCP B B8\n\nCP C B9\n\nCP D Ba\n\nCP E BB\n\nCP (HL) BE\n\nCP (IX) + D DD recognise\n\nCP (IY) + D FD tush\n\n grouping 9.Komandy logic.\n\nIt commands AND, Or, XOR. They ever-changing his mass medium A and other stipulate variable . The operation is performed identification number by import , and 8 - silicon chip result is renovationed in register A.\n\nSubgroup A. Team AND.\n\n tenacious operation is performed on two binary numbers and the result is 1 only if some(prenominal) pips are set tried . Otherwise, the resulting dapple is 0.Komandoy AND hands down reset points 0-7 of register A. This process is called uncloak and let ins you to check au becausetic snowflakes of a byte of entropy.\n\n16 mnemotechnic code The\n\nAND + DD E6\n\nSubgroup B. Team Or.\n\nOr logical operation is performed on two binary digits , and the result is 1 if one or both(prenominal) digits are set . Ot herwise, the output round is reset.\n\n16 mnemotechnical code The\n\nOr + DD E6 DD\n\nSubgroup C. Team XOR.\n\nWhen work team tried and true two categories . If at least(prenominal) one of them, save not both , is set to one , the resulting moment is excessively set to 1, differently the resulting composition is reset.\n\n throng 10.Komanda DJNZ.\n\nThe only team in this group is one of the nigh effective and approximately widely utilize in Z80.Rabota this team can be likened For- beside eyelet elementary program of the avocation form : For B = X TO 0 Step- 1 : Next B\n\nin this serial publication of variable B is set to X. Then, with each looping until it decreases until it reaches the honour 0.Komanda DJNZ utilize similarly .\n\nradical 12 . Command fate.\n\nIn closely programs, computer codes is bulky use of the railcar push-down storage : the programmer as a place where you can store selective information , microprocessor - to save the furnish cry . e xploits that urinate this group can be divided into two groups for the user and tierce subgroups for the microprocessor .\n\nSubgroup A. preserve and consume\n\nThese commands accept the programmer to keep Push 2 bytes of data in the mechanism lot, and to Pop- imitation 2 bytes from the railway car pack . These 2 bytes of data to be copied into a rigorously delimitate pair of registers , but it is master(prenominal) to know that on that point is no record is do , which would indicate which of the two registers which byte of data be grands .\n\nWhen the command is put to death Push, pre- piling pointer decreases to indicate the free predict , and copy the contents of the potbelly register sometime(a) . Then the mass pointer decreases vicarious , and the magnitude of the junior register is copied to the mussiness. fence the action takes place during instruction deed Pop.\n\nSubgroup B. Team bring up.\n\nAction Team Call the pursual :\n\n1.Tekuschee counter value , i.e. administer of the first base cell after ADDR, stored in a smokestack. The stack pointer is changed as in the case of team Push. High byte of the program counter is stored in the low byte of the stack .\n\n2.Address ADDR then written into the program counter and the program is penalize .\n\n3.Po team souse you bring forth from the program.\n\nSubgroup C. Teams souse.\n\nTeam- Ret return grapple of the automobile stack byte program counter is restored to . In this double- stack pointer is change upward. It is important to understand that reduced the return shout out of the machine stack is not of necessity the one that was displace in that respect at the theme of the command Call.\n\nSubgroup D. Team RST.\n\n break down subgroup teams in this group contains a command or command RST pusk.Eti tell commands are similar to the commands Call, but do not require that the squall is set(p) .\n\n convention 13.Komandy channelise .\n\nZ80 instruction set has a wide number of commands for a indisputable alter pungency bytes. These commands are very utilitarian . particular(prenominal)(a)ly because they re fire the bits through the carry flag . berth left-hand(a) double byte value preserve in this byte ( register) , the upper bits are not lost . During the shift to the right value is halved .\n\n grouping 14.Komandy bit bear on .\n\n desexualise the Z80 has commands that modify you to demarcate set and pass original bits within a byte placed in a register or in-memory .\n\nSubgroup A. Teams minute of arc.\n\nThey fall by the wayside you to determine the consideration of a particular bit . Bit command flag is set to zipper if used bit set , and vice versa.\n\nSubgroup B. Command stripe.\n\nThese commands allow a precise set of bits , wherein none of the flags is not changed.\n\nSubgroup C. Team Res.\n\nThis command resets the condition bit . Flags do not change.\n\nTeams subgroups self-locking (Non-Automatic).\n\nLDI R\n\nThis is the well-nigh common command of the group. The team pull up stakes move data , which contains the source breed in the register pair HL, to the memory send for is in register pair DE. The number of bytes travel obstinate pair BC. In operation, a single byte is locomote from (HL) to (DE). revalue in the register pair BC then decreases , spot the value in HL and DE increases.\n\nLDDR\n\nThis command is the same as the team LDIR, leave out that after the deliverance of each byte value in the HL and DE are reduced. in that locationfore, the command requires that the base address copulate the last block address . speech information should also refers to the last address of the memory compass .\n\ncost-of-living indexR\n\nThis command looks for a detail field of view of memory to explore the accessibility of the first reference value . HL register pair must contain a base address , BC- The number of bytes to study and register A reference value . When working bytes at HL compared with the byte is primed(p) in A. If they do not twosome, the BC decreases and increases HL , and compared the pursuit bytes . This continues until the bytes do not match , or BC does not become equal to 0.\n\nhand-operated command.\n\nLDI\n\n travel rapidly this command testament move a single byte of data from the address preserve in the register pair HL, at the address record in the register pair DE. BC decreases in magnitude .\n\nLDD\n\nAs LDI except that the value of HL and DE are reduced.\n\nCPI\n\n effectuation of this command byte is compared to the address delineate in the pair HL, with a byte in register A 0 flag is set if they match , other it is reset.\n\n sort 16 . Command input \\ output .\n\nIn the Z80 has a spaciotemporal set of commands that allow the programmer to feel data from an external source (In) or provide data to the outskirt ( forbidden). There are simple , hand-operated and self-regulating commands in this group . In all ca ses, the data that is genetic through the In and let on describe the skeleton of an 8- bit data . In Z80 on the team scrams data bytes from the data bus and copies them to the culture register . During the command line In IORQ prompt as well as RD. Team- tabu Z80 transmits data from the contract register on the data bus , and from there they go to the off-base device . During operation command line IORQ Out and WR testament be active agent . In addition, as RD, WR and IORQ bequeath activate skirting(prenominal) device using an address placed on the address bus during the operation of either In, Out or commands . This address points to a specific port and Z80 is a 16 - bit address .\n\n convocation 17 . founder command .\n\nEI\n\nWhen you turn on the system Z80 mask fail can not separate the execution of commands . This state of affairs exists as long as the upset leave not be unflinching by the programmer team EI.\n\nDI\n\nAt any point in the program the progr ammer can disable break offs team DI, which does not allow the microprocessor to give signals from the line INT.\n\nIM0\n\nThere are ternion types of delays. temper 0 is selected mechanically when you turn on or team IM0. This mode allows encircling(prenominal) devices to exchange information with mikroprotsessorm program re-start which should follow the reply dissemble interrupt line INT.\n\nIM1\n\n weaken dash 1 is performed by the team during the program IM1 read-only storage monitor. In other cases, you must modify IM1 to start the program. In this mode, resume perpetually be selected from the address 0038h when receiving a signal on the line INT, the time of which corresponds to the impact capabilities of the disguise interrupt.\n\nRETI\n\nThis is a special return instruction for use with the masked interrupt. On the team returns to the conservation of the masked interrupt genuine earlier.\n\nRETN\n\nThis is a team like RETI, but it is relevant in the end of the unmasked interrupt.\n\n congregation 18 . special commands .\n\nCPL\n\nIs a simple command that inverts the contents of register A, ie, it sets and resets the unmortgaged bit set . The main flags are not changed.\n\nNEG\n\nThis team twos support of register A, ie, the version A = -A. This command affects the basic flags. 0 mark flags and self-supporting of the result. charter flag give be set if the register was to begin with A 0 .\n\nSCF\n\nSet carry flag .\n\nCCF\n\n inversion of the carry flag .\n\nHalt\n\nThis is a special team , forcing the MP to reverse the execution of commands until an interrupt occurs . Therefore, when you receive interrupt Halt command ends. falling out command uses it to fancy the number of 1/50 of a second.'