RAM (Random Access Memory) yog lub cim xeeb nkag tau nrawm uas khaws cov ntaub ntawv thaum nws ua haujlwm thaum ROM (Nyeem Tsuas Nco) khaws cov ntaub ntawv mus tas li uas siv rau nws txoj haujlwm, xws li cov ntaub ntawv rau khau raj lub computer. Yog li, qhov sib txawv tseem ceeb ntawm RAM thiab ROM yog nyob rau hauv txoj kev cov ntaub ntawv khaws cia rau hauv lawv; qhov chaw cia hauv RAM yog ib ntus thaum qhov chaw cia hauv ROM yog qhov ruaj khov.
Ib lub computer, zoo li tib neeg lub hlwb, xav tau kev nco khaws cov ntaub ntawv xav tau. Piv txwv li, tib neeg tuaj yeem ntxiv ob tus lej ua ke thiab tsim cov txiaj ntsig raws li tus qauv uas nws tau kawm thiab nco. Ib yam li ntawd, lub computer yuav tsum tuav txoj hauv kev thiab cov ntaub ntawv hauv lub cim xeeb kom ua haujlwm. RAM thiab ROM yog ob qho tib si sib txawv ntawm kev nco siv nyob rau hauv ib lub computer los ua kom ceev thiab pab kom nws nkag tau cov ntaub ntawv khaws cia hauv lub computer. Txhua lub khoos phis tawj tuaj nrog qee qhov ntawm lub cev nco, uas yog nyob rau hauv daim ntawv ntawm cov chips uas tuav cov ntaub ntawv.
YRAM yog dab tsi?
RAM yog cov ntawv luv ntawm Random Access Memory. Raws li lub npe txhais, kev siv lossis kev nkag mus rau lub cim xeeb yog random txij li lub microprocessor nyeem lub cim xeeb thiab sau rau nws sai heev. Xav txog lub khoos phis tawj uas xav tau ntxiv ob tus lej uas tus neeg siv nkag. Thaum tus neeg siv nkag mus rau ob tus lej, lub khoos phis tawj khaws cov lej hauv RAM. Tom qab ntawd, nws khaws cov txiaj ntsig hauv RAM rau tus neeg siv nyeem. Qhov no yog li cas lub computer lossis microprocessor nyeem thiab sau cov ntaub ntawv hauv RAM. Ib yam li ntawd, thaum ua tiav cov haujlwm, lub khoos phis tawj khaws cov ntaub ntawv xav tau los ntawm hard disk drive hauv RAM kom nkag tau sai.
Yuav ua li cas cov ntaub ntawv khaws cia hauv RAM
A RAM yog ib qho kev sib txuas ua ke ntawm lub cim xeeb hlwb uas yog circuits ntawm logic rooj vag. Txhua lub cim xeeb ntawm tes muaj qhov chaw nyob uas lub microprocessor txheeb xyuas qhov chaw sau cov ntaub ntawv lossis los ntawm qhov twg los nyeem nws. Ib lub cim xeeb ntawm tes tuaj yeem khaws cia ib qho me ntsis ntawm cov ntaub ntawv, thiab feem ntau, lub cim xeeb ntawm lub hlwb tau teeb tsa raws li kev sau npe los tuav 8 ntsis cov ntaub ntawv dav. Qhov dav ntawm cov ntaub ntawv yuav txawv nyob ntawm seb hom RAM. Ntawd yog, 16-ntsis RAM muaj 16-ntsis sau npe, qhov 8-ntsis RAM muaj 8-ntsis sau npe.
Cov npe sau saum toj no muaj ob hom kev sib txuas: kab chaw nyob thiab cov kab ntawv. Cov logic '1' thiab '0' ua ke muab tso rau ntawm cov kab chaw nyob ua kom cov npe uas haum rau kev sib xyaw tshwj xeeb thiab ua rau nws nyeem lossis sau ntawv. Txawm li cas los xij, cov ntaub ntawv khaws cia hauv cov ntawv sau npe RAM no tsuas yog ib ntus xwb, yog li lawv ploj mus thaum lub hwj chim tawm. Qhov no ua rau RAM lub cim xeeb tsis zoo.
Daim duab 01: RAM
Type of RAM
Muaj ntau hom RAMs siv hauv computer; Cov hom tseem ceeb yog Static RAM (SRAM) thiab Dynamic RAM (DRAM). SRAM tau nrawm dua ntawm kev nkag mus thiab tus nqi tsim khoom yog siab dua DRAMs. Yog li ntawd, SRAM yog siv los ua lub cim xeeb ntawm microprocessor nti. DRAM, ntawm qhov tod tes, yog qeeb me ntsis thiab sib piv qis dua. DRAMs yog siv sab nraud rau microprocessor ntawm lub motherboard. Qee zaum, lub khoos phis tawj ua ib qho kev faib cais ntawm lub hard disk ua RAM los tsim rau lub cev siv ntau dhau ntawm RAM. Cov txheej txheem no ua rau lub khoos phis tawj ua haujlwm qeeb vim qhov no yuav tsum tau sau thiab nyeem cov ntaub ntawv hauv cov ntaub ntawv hu ua nplooj ntawv ntawm lub hard disk. Hom RAM no hu ua virtual RAM.
ROM yog dab tsi?
ROM yog cov lus luv rau Read-Tsuas Nco. Tsis zoo li RAM, ROM yog lub cim xeeb tsis hloov pauv; Txawm hais tias lub zog raug tshem tawm ntawm ROM nti, cov ntaub ntawv khaws cia tseem nyob hauv lawv cov npe. ROMs, feem ntau, muaj cov ntaub ntawv khaws cia ua ntej thaum lawv tsim. Rau cov khoos phis tawj, ROM yog qhov tseem ceeb los khaws cov kev pabcuam tsis hloov pauv; Piv txwv li, BIOS, uas raug tua thaum pib (khau raj).
Disadvantages of ROM
Muaj ntau qhov tsis zoo ntawm ROMs, thiab qhov tsis zoo tseem ceeb yog qhov tsis muaj peev xwm hloov lossis hloov kho cov yam ntxwv ntawm lub firmware. Yog tias cov chaw tsim khoom tau programmed nws nrog malfunctioning firmware, ces tag nrho cov chips yuav tsum tau rov qab thiab hloov ib tug los ntawm ib tug. Lwm qhov tsis zoo yog tias ROMs tsis muaj txiaj ntsig hauv R & D ua haujlwm txij li ntau lub versions ntawm lub firmware yuav tsum tau kuaj los ntawm tus programmer ua ntej tshaj tawm cov khoom kawg.
Type of ROM
Ib qho rub tawm tau programmable ROM (EPROM) qhov twg lub firmware tuaj yeem sau rov qab los ntawm tus programmer tau qhia kom kov yeej cov teeb meem hais saum toj no. Txawm li cas los xij, qhov kev tshem tawm xav tau lub teeb pom kev siab UV, ua rau nws tseem nyuaj. Raws li kev daws teeb meem rau qhov no, cov khoom siv hluav taws xob tshem tawm cov programmable ROM (EEPROM) tau raug qhia rau cov programmers, kom lawv tuaj yeem siv rau ntawm lub txaj nws tus kheej, thiab tuaj yeem rov ua dua dua.
Figure 02: EEPROM
Flash nco, siv hauv USB drives thiab niaj hnub laptops ua lub hard drive, yog ib qho kev txhim kho ntxiv ntawm EEPROM uas siv cov nti hauv cheeb tsam zoo heev. Cov ntaub ntawv rov sau tau CDs thiab DVDs kuj suav tias yog kev nce qib ntawm CD thiab DVD ROMs.
Qhov txawv ntawm RAM thiab ROM
RAM vs ROM |
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| Cov ntaub ntawv tuaj yeem khaws cia thiab rov qab los ntawm RAM (Random-Access Memory). | Cov ntaub ntawv tsuas yog nyeem los ntawm ROM (Read-Tsuas Nco). |
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| Lub sijhawm nkag mus yog luv heev hauv RAM. Lub khoos phis tawj siv nws nrawm los khaws cov ntaub ntawv uas xav tau ntau zaus. | Lub sijhawm nkag mus tau ntev hauv ROM. Nws tsis tuaj yeem siv los nyeem nrawm. |
| RAM yog lub cim xeeb tsis hloov pauv, yog li thaum lub zog hluav taws xob poob, cov ntaub ntawv raug tshem tawm ntawm lub cim xeeb. | ROM yog lub cim xeeb uas tsis muaj teeb meem. Yog hais tias nws tsis yog erasable, cov ntaub ntawv tseem nyob rau hauv cia kom txog thaum lub hardware puas. |
| RAM yog siv rau hauv lub cache thiab lub cim xeeb tseem ceeb ntawm lub khoos phis tawj vim nws nrawm, tus nqi tsim khoom yog siab thiab thaj tsam ntawm ib chav nco yog loj dua. | ROMs yog siv los khaws cov ntaub ntawv mus tas li, tab sis cov ntaub ntawv siv tsawg dua li kev teeb tsa software, ib zaug nkaus xwb-siv BIOS hauv cov khoos phis tawj vim lawv tau tsim muaj peev xwm loj dua thiab cov nqi tsim khoom tsawg dua. |
Summary – RAM vs ROM
RAM yog qhov ceev ceev cia ib ntus rau cov ntaub ntawv uas yog siv los khaws cov txiaj ntsig uas tau siv sai. Hauv qhov sib piv, ROMs yog hom kev nco mus tas li thiab tsis zoo li RAMs, cov ntaub ntawv poob yuav tsis tshwm sim txawm tias qhov hluav taws xob raug tshem tawm. Qhov no yog qhov sib txawv tseem ceeb ntawm RAM thiab ROM. ROMs yog qhov tsis zoo nyob rau hauv kev siv txij li thaum ib zaug firmware tau sau rau hauv ROM, nws tsis tuaj yeem hloov kho rau kev txhim kho lossis kho. Yog li, ROMs kuj tau qhia nrog kev nyeem ntawv thiab sau muaj peev xwm zoo li RAMs. Tab sis kev nyeem / sau ua haujlwm ntawm RAMs nrawm dua ROM.
