{"id":15819,"date":"2022-06-29T10:05:19","date_gmt":"2022-06-29T08:05:19","guid":{"rendered":"https:\/\/popelky.cz\/?p=15819"},"modified":"2023-01-21T20:46:38","modified_gmt":"2023-01-21T19:46:38","slug":"eeprom-programovatelna-soucastka","status":"publish","type":"post","link":"https:\/\/popelky.cz\/verze7-0\/komerce\/eeprom-programovatelna-soucastka.html","title":{"rendered":"EEPROM \u2013 programovateln\u00e1 sou\u010d\u00e1stka"},"content":{"rendered":"

Views: 52<\/p>

EEPROM (Electrically-Erasable Programmable Read-Only Memory) je typ po\u010d\u00edta\u010dov\u00e9 pam\u011bti. Lze do n\u00ed zapisovat opakovan\u011b \u00fadaje.<\/p>\n

 <\/em>Co je to EEPROM?<\/p>\n

EEPROM je energeticky nez\u00e1visl\u00e1 pam\u011b\u0165. <\/strong>Jakmile dojde k odpojen\u00ed nap\u00e1jen\u00ed, nedoch\u00e1z\u00ed ke ztr\u00e1t\u011b obsahu. EEPROM m\u00e1 malou kapacitu pam\u011bti (pojme jen n\u011bkolik des\u00edtek kB), ale vzhledem k nest\u00e1losti a n\u00edzk\u00fdm v\u00fdrobn\u00edm n\u00e1klad\u016fm m\u00e1 \u0161irok<\/strong>\u00e9 vyu\u017eit\u00ed.<\/strong> Pou\u017e\u00edv\u00e1 se v produktech, kdy je pot\u0159eba u\u0161et\u0159it jen minimum dat, nap\u0159\u00edklad v p\u0159\u00edpad\u011b firmware hardwaru. <\/p>\n

A\u010dkoliv m\u00e1 skute\u010dn\u011b malou pam\u011b\u0165, v praxi se pou\u017e\u00edvaj\u00ed \u0159e\u0161en\u00ed, kdy mus\u00ed b\u00fdt tato pam\u011b\u0165 n\u011bkolikan\u00e1sobn\u011b v\u011bt\u0161\u00ed. Nej\u010dast\u011bji se jedn\u00e1 o p\u0159enosn\u00e9 po\u010d\u00edta\u010de, kam se ukl\u00e1daj\u00ed soubory pro BIOS. <\/p>\n

Jak se zapisuje a \u010dte v EEPROM?<\/h3>\n

P\u0159epis \u010di z\u00e1pis do pam\u011bti EEPROM lze prov\u00e1d\u011bt po jednotliv\u00fdch bytech. Naopak v pam\u011bti FLASH se maz\u00e1n\u00ed a z\u00e1pis prov\u00e1d\u00ed hromadn\u011b. Aby bylo mo\u017eno z\u00e1pis prov\u00e1d\u011bt, je nutn<\/strong>\u00e9 pou\u017e\u00ed<\/strong>t speci\u00e1ln\u00ed p\u0159\u00edstupov<\/strong>\u00e9 procedury, vyrovn\u00e1vac\u00ed pam\u011b\u0165 <\/strong>a RAM<\/strong>. Naopak EEPROM \u010dip nevy\u017eaduje ke \u010dten\u00ed a z\u00e1pisu \u017e\u00e1dn\u00e9 slo\u017eit\u00e9 operace. Je v\u0161ak pot\u0159eba po\u010d\u00edtat s pomalej\u0161\u00edm z\u00e1pisem i \u010dten\u00edm, ne\u017e je tomu pr\u00e1v\u011b u Flash pam\u011bt\u00ed. Rychlost z\u00e1pisu u EEPROM je p\u0159<\/strong>ibli\u017en\u011b 3,3 ms \/ bu\u0148ku<\/strong>.<\/p>\n

U EEPROM<\/a> lze prov\u00e1d\u011bt \u010dten\u00ed z pam\u011bti donekone\u010dna, ale prov\u00e1d\u011bn\u00ed zm\u011bn je mo\u017en<\/strong>\u00e9 pouze omezen\u011b<\/strong>. Z\u00e1le\u017e\u00ed to na konkr\u00e9tn\u00edm modelu a v\u00fdrobci. Lze vyb\u00edrat modely s 10 000 a\u017e 1 000 000 cykly. Jakmile po\u010det dan\u00fdch cykl\u016f p\u0159ekro\u010d\u00edte, pam\u011b\u0165 p\u0159est\u00e1v\u00e1 fungovat. Ka\u017ed\u00e1 operace, kdy dojde k vymaz\u00e1n\u00ed pam\u011b\u0165ov<\/strong>\u00e9 bu\u0148ky, zp\u016f<\/strong>sob\u00ed postupn<\/strong>\u00e9 zhor\u0161ov\u00e1n\u00ed vlastnost\u00ed izolantu.<\/strong> V d\u016fsledku toho doch\u00e1z\u00ed k \u00faniku elektrick\u00e9ho n\u00e1boje a t\u00edm k pomal\u00e9mu maz\u00e1n\u00ed obsahu bu\u0148ky. \u010c\u00edm v\u00edce cykl\u016f vymaz\u00e1n\u00ed bylo provedeno, t\u00edm je proces rychlej\u0161\u00ed.<\/p>\n

Konstrukce EEPROM<\/h3>\n

Pam\u011b\u0165ov\u00e9 bu\u0148ky EEPROM jsou postaveny na b\u00e1zi tranzistor\u016f s efektem pole sest\u00e1vaj\u00edc\u00edch ze dvou hradel: plovouc\u00ed a \u0159\u00edd\u00edc\u00ed. Pou\u017eit\u00ed ten\u010d\u00ed vrstvy oxidu k\u0159emi\u010dit\u00e9ho ne\u017e v p\u0159\u00edpad\u011b EPROM mezi plovouc\u00edm hradlem a kolektorem a siln\u00e9 elektrick\u00e9 pole umo\u017e\u0148uje tunelovac\u00ed jevy pou\u017e\u00edvan\u00e9 p\u0159i aktivaci tranzistoru. P\u0159im\u011b\u0159en\u011b vysok\u00e9 nap\u011bt\u00ed a polarizace \u0159\u00eddic\u00edho hradla\/odvodu zp\u016fsobuj\u00ed hromad\u011bn\u00ed nebo vyb\u00edjen\u00ed n\u00e1boj\u016f plovouc\u00edho hradla.<\/p>\n

\"shutterstock<\/p>\n

Nab\u00edjen\u00ed hradla uzamkne tranzistor, co\u017e odpov\u00edd\u00e1 logick\u00e9 „0“. V\u00fdboj nut\u00ed tranzistor k \u010dinnosti, co\u017e odpov\u00edd\u00e1 v\u00fdskytu logick\u00e9 „1“. M\u00e1te-li z\u00e1jem o EEPROM \u010di jin\u00e9 sou\u010d\u00e1stky, nav\u0161tivte str\u00e1nky tme.eu<\/a>.<\/p>\n

Zdroj foto: raigvi \/ Shutterstock.com<\/p>\n","protected":false},"excerpt":{"rendered":"

Views: 52EEPROM (Electrically-Erasable Programmable Read-Only Memory) je typ po\u010d\u00edta\u010dov\u00e9 pam\u011bti. Lze do n\u00ed zapisovat opakovan\u011b \u00fadaje.<\/p>\n","protected":false},"author":3,"featured_media":18869,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[51],"tags":[],"class_list":["post-15819","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-komerce"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t