{"id":653,"date":"2013-04-07T13:58:01","date_gmt":"2013-04-07T11:58:01","guid":{"rendered":"https:\/\/zz-indigo.mavipet.sk\/?page_id=653"},"modified":"2013-04-07T13:58:01","modified_gmt":"2013-04-07T11:58:01","slug":"mc68000-bus","status":"publish","type":"page","link":"https:\/\/zz-indigo.mavipet.sk\/?page_id=653","title":{"rendered":"MC68000 BUS"},"content":{"rendered":"<p>Pre spr\u00e1vnu pr\u00e1cu akceler\u00e1tora je nutn\u00e9 \u010do najlep\u0161ie simulova\u0165 procesor na nat\u00edvnej frekvencii amigy.<\/p>\n<p>MC68000 pracuje z okol\u00edm po\u010das 4 taktov rozdelen\u00fdch do 8 stavov. Ke\u010f\u017ee Amiga 600 nepo\u010d\u00edta z pou\u017eit\u00edm zariaden\u00ed z rodiny 6800 nemus\u00edme rie\u0161i\u0165 !VPA, !VMA\u00a0 a !E sign\u00e1ly. Tie\u017e to dovolilo pou\u017ei\u0165 dostupnej\u0161\u00ed 68SEC000 Ktor\u00fd tieto sign\u00e1ly nepozn\u00e1.<\/p>\n<ul>\n<li>S0 &#8211; procesor nastav\u00ed FC0 a\u017e FC2\u00a0 a R\/!W d\u00e1 do stavu H<\/li>\n<li>S1 &#8211; procesor nastav\u00ed Adresu<\/li>\n<li>S2 &#8211; procesor nastav\u00ed !AS<\/li>\n<ul>\n<li>Pri \u010d\u00edtan\u00ed aj\u00a0 !UDS !LDS<\/li>\n<li>Pri z\u00e1pise nastav\u00ed aj R\/!W<\/li>\n<\/ul>\n<li>S3 &#8211; procesor &#8222;ni\u010d nerob\u00ed&#8220;<\/li>\n<li>S4 &#8211; procesor \u010dak\u00e1 na !DTACK pr\u00edpadne !BERR od zariadenia. Ak nepr\u00edde vlo\u017e\u00ed \u010dakaj\u00face cykli medzi S4 a S5<\/li>\n<ul>\n<li>Pri z\u00e1pise nastav\u00ed aj\u00a0 !UDS !LDS<\/li>\n<\/ul>\n<li>S5 &#8211; procesor &#8222;ni\u010d nerob\u00ed&#8220;<\/li>\n<li>S6 &#8211; procesor<\/li>\n<ul>\n<li>Pri \u010d\u00edtan\u00ed pre\u010d\u00edta d\u00e1ta z pam\u00e4te<\/li>\n<li>Pri z\u00e1pise nerob\u00ed ni\u010d<\/li>\n<\/ul>\n<li>S7 &#8211; procesor vr\u00e1ti !AS, !UDS a !LDS. Zariadenie !DTACK a !BERR<\/li>\n<ul>\n<li>Pri z\u00e1pise aj R\/!W<\/li>\n<\/ul>\n<\/ul>\n<pre>Popis   | Citanie 16 bit                | Z\u00e1pis 8 bit horn\u00e9 bity        |\nState   S0  S1  S2  S3  S4  S5  S6  S7  S0  S1  S2  S3  S4  S5  S6   S7 S0\nCLK    _----____----____----____----____----____----____----____----____----\n!AS    ---------________________________--------________________________----\n!UDS   ---------________________________----------------________________----\n!LDS   ---------________________________------------------------------------\nR\/!W   -----------------------------------------________________________----\n!DTACK -----------------________________----------------________________----\nD15-D8 xxxxxxxxxxxxxxxxx================xxxxxxxxxxxx====================xxxx\nD7-D0  xxxxxxxxxxxxxxxxx================xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx\n\nPozn\u00e1mky:\n= Hodnota na zbernici ktor\u00e1 sa aktu\u00e1lne nemen\u00ed\nx Nieje podstatn\u00fd stav\n_ L stav \n- H stav<\/pre>\n<p>V pr\u00edpade synchr\u00f3nneho akceler\u00e1tora m\u00e1me pr\u00e1cu zjednodu\u0161en\u00fa sta\u010d\u00ed vhodne vynucova\u0165 wait stavy.<\/p>\n<pre>Popis         | Citanie 16 bit                | Z\u00e1pis 8 bit horn\u00e9 bity        |\nState Amiga   S0  S1  S2  S3  S4  S5  S6  S7  S0  S1  S2  S3  S4  S5  S6   S7 S0\nState ACC     S0S1S2S3S4SwSwSwSwSwSwSwSwS5S6S7S0S1S2S3S4SwSwSwSwSwSwSwSwS5S6S7S0S1\nCLK Amiga    _----____----____----____----____----____----____----____----____----\nCLK ACC      _--__--__--__--__--__--__--__--__--__--__--__--__--__--__--__--__--__\n!AS Amiga    ---------________________________--------________________________----\n!AS ACC      -----____________________________----____________________________----\n!UDS Amiga   ---------________________________----------------________________----\n!UDS ACC     -----____________________________------------____________________----\n!LDS Amiga   ---------________________________------------------------------------\n!LDS ACC     -----____________________________------------------------------------\nR\/!W Amiga   -----------------------------------------________________________----\nR\/!W ACC     -------------------------------------____________________________----\n!DTACK Amiga -----------------________________----------------________________----\n!DTACK ACC   -------------------------________------------------------________----<\/pre>\n<p>Pri poh\u013eade na priebehy napadne myslienka v\u00f4bec to ma zmysel? Ale \u00e1no Medzi Stavmy S7 a S0 nie s\u00fa uk\u00e1zan\u00e9 takty nutn\u00e9 na vykonanie in\u0161trukcie. Tam je priestor v\u010faka ktor\u00e9mu akceler\u00e1tor ur\u00fdchli\u00a0 Amigu. Tie\u017e si treba uvedomi\u0165 ze aj samotn\u00e1 Amiga vyvol\u00e1va wait stavy, a to v pr\u00edpade ke\u010f sa pristupuje co Chip RAM.<\/p>\n<p>K problematike sa d\u00e1 pristupova\u0165 r\u00f4zne. Napr\u00edklad fakt ze Amiga pracuje o pol taktu posunuto oproti CPU dovo\u013euje ist\u00fa vo\u013enos\u0165 v generovan\u00ed Niektor\u00fdch sign\u00e1lov. Na druh\u00fa stranu m\u00f4\u017ee to vyvol\u00e1va\u0165 r\u00f4zne ne\u0161tandardn\u00e9 stavy. V pr\u00edpade synchr\u00f3nneho akceler\u00e1tora sa asi moc prejavova\u0165 nebud\u00fa ale v pr\u00edpade asynchr\u00f3nneho one nieje n\u00fadza. \u010co je aj d\u00f4vod pre\u010do som pri\u0161iel k z\u00e1veru \u017ee moja kon\u0161trukcia bez zmien nieje pre asynchr\u00f3nny m\u00f3d pou\u017eite\u013en\u00e1<\/p>\n<p>Najjednoduch\u0161\u00ed\u00a0 akceler\u00e1tor navrhol Livio Plos a Joerg Richter. Tento akceler\u00e1tor len ovl\u00e1da posunutie !DTACK a ostatn\u00e9 riadiace sign\u00e1ly nech\u00e1va nedotknut\u00e9.<\/p>\n<p>Osobne si ale mysl\u00edm \u017ee zarovn\u00e1vanie aj ostatn\u00fdch sign\u00e1lov na stabilite len prid\u00e1.<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Pre spr\u00e1vnu pr\u00e1cu akceler\u00e1tora je nutn\u00e9 \u010do najlep\u0161ie simulova\u0165 procesor na nat\u00edvnej frekvencii amigy. MC68000 pracuje z okol\u00edm po\u010das 4 taktov rozdelen\u00fdch do 8 stavov. Ke\u010f\u017ee Amiga 600 nepo\u010d\u00edta z pou\u017eit\u00edm zariaden\u00ed z rodiny 6800 nemus\u00edme rie\u0161i\u0165 !VPA, !VMA\u00a0 a &hellip; <a href=\"https:\/\/zz-indigo.mavipet.sk\/?page_id=653\">Pokra\u010dova\u0165 v \u010d\u00edtan\u00ed <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":94,"menu_order":2,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-653","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/zz-indigo.mavipet.sk\/index.php?rest_route=\/wp\/v2\/pages\/653","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/zz-indigo.mavipet.sk\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/zz-indigo.mavipet.sk\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/zz-indigo.mavipet.sk\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/zz-indigo.mavipet.sk\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=653"}],"version-history":[{"count":0,"href":"https:\/\/zz-indigo.mavipet.sk\/index.php?rest_route=\/wp\/v2\/pages\/653\/revisions"}],"up":[{"embeddable":true,"href":"https:\/\/zz-indigo.mavipet.sk\/index.php?rest_route=\/wp\/v2\/pages\/94"}],"wp:attachment":[{"href":"https:\/\/zz-indigo.mavipet.sk\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=653"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}