2-Mavzu. Kompyuterlarni tashkil qilishning raqamli mantiqiy asoslari

Many times _ _ programmable DSQ
Such DSQ programming procedure usually two stage included _ _ _ takes : first in turn of cells all or a part of the contents are removed , then _ _ new information _ _ is written .
Permanent save device this in the classroom a how many groups allocated :

• EPROM (Erasable Programmable ROM) - disabled programmable DSQ);
• EEPROM (Electrically Erasable Programmable ROM ) with deleted programmable DSQ);
• flash memory ;
• PCM (Phase Change Memory) - phase memory .

Ko’p marta dasturlanadigan DSQ
Bunday DSQ dasturlash protsedurasi odatda ikki bosqichni o’z ichiga oladi: birinchi navbatda yaycheykalarning barchasi yoki bir qismining tarkibi o'chiriladi, so'ngra yangi ma'lumotlar yoziladi.
Doimiy saqlash qurilmasi ushbu sinfida bir nechta guruhlar ajratilgan:

• EPROM (Erasable Programmable ROM — o’chirib dasturlanadigan DSQ);
• EEPROM (Electrically Erasable Programmable ROM — elektr bilan o’chirilib dasturlanadigan DSQ);
• flesh-xotira;
• PCM (Phase Change Memory) — fazali xotira.

EPROM chips . EPROPM ga the data is the same as in PROM such as electricity signals using is written , however write operation before chips ultraviolet radiation effect to do through all yaycheyka content a kind of condition must be quoted ( deleted ) . Crystal uncha big not quartz to the mirror has which is ceramic to the body wrapped through which _ radiation instead is increased . Information random no ilishini prevent get for radiation then quartz window transparent not film with closes . Close process a lot times completion possible . Everyone _ turn off about 20 minutes to be continued reaches _ Programming cycle a how much face milliseconds takes _ Reading time to ROM and DRAM indicators close _
With PROM EPROM chips in comparison expensive , but plentiful times again programming options often hal seeker importance has _
EPROM mikrosxemalari. EPROPM ga ma’lumotlar, xuddi PROM da bo’lgani kabi, elektr signallari yordamida yoziladi, lekin yozish operatsiyasidan oldin mikrosxemani ultrabinafsha nurlanishiga ta’sir qilish orqali barcha yaycheyka tarkibini bir xil xolatga keltirish (o’chirish) kerak. Kristall uncha katta bo’lmagan kvars oynaga ega bo’lgan, keramika korpusga o’ralgan bo’lib, u orqali nurlanish amalga oshiriladi. Ma’lumotlar tasodifiy yo’q ilinishini oldini olish uchun nurlanishdan keyin kvars oynasi shaffof bo’lmagan plyonka bilan yopiladi. O’chirish jarayoni ko’p marta bajarilishi mumkin. Har bir o’chirish taxminan 20 daqiqa davom etadi. Dasturlash sikli bir necha yuz millisekundlarni oladi. O’qish vaqti ROM va DRAM ko’rsatkichlariga yaqin.
PROM bilan taqqoslaganda EPROM mikrosxemalari qimmatqoq, ammo ko’p marta qayta dasturlash imkoniyatlari ko’pincha hal qiluvchi ahamiyatga ega.
EEPROM chips . A lot times programmable of memory yanda to himself specific options electric with removable constant The memory is EEPROM . To this memory information write and turn off bytes on instead increase , delete esa separately process not _ _ write on time automatic instead increasing stage . Writing operation to read than noticeable degree more takes time - everyone _ byte for hundreds microseconds . Like EPROM on the chip a kind of information save principles applied . EPROM ni in programming special programmer need it's not and it is a chip in itself instead is increased .
In general when received , EEPROMs to EPROM than more expensive and chip of cells denser to ' plamiga has ya ' ni less to size has _