{"id":222150,"date":"2025-05-31T05:40:16","date_gmt":"2025-05-31T05:40:16","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=222150"},"modified":"2025-05-31T05:40:18","modified_gmt":"2025-05-31T05:40:18","slug":"how-many-256x8-roms-are-needed-to-make-a-4096x8-rom-and-what-kind-of-decoder-should-be-used","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/05\/31\/how-many-256x8-roms-are-needed-to-make-a-4096x8-rom-and-what-kind-of-decoder-should-be-used\/","title":{"rendered":"How many 256X8 ROMs are needed to make a 4096×8 ROM and what kind of decoder should be used"},"content":{"rendered":"\n
QUESTION 4 4. How many 256X8 ROMs are needed to make a 4096×8 ROM and what kind of decoder should be used? (Use only 256X8 ROMs) A # of 256×8 ROMs : 4, type of decoder : 2×4 OB t of 256X8 ROMs : 8, type of decoder: 3X8 c, # of 256×8 ROMs : 16, type of decoder: 3X8 D # of 256X8 ROMs : 16, type of decoder : 4×16 QUESTION 5 5. To compose a 4 096×1 mux from 8×1 muxes only, how many select inputs are needed and how many 8X1 muxes are needed? @ A select inputs: 3-bits, # of 8X1 muxes : 512 select inputs: 4-bits, # of 8X1 muxes : 585 “select inputs: 12-bits, # of 8×1 muxes : 512 select inputs: 12-bits, # of 8X1 muxes : 585 B D QUESTION 6 6. To compose a 2048X64 ROM using only 256×8 ROMs, how many 256X8 ROMs are needed and what kind of decoder should be used? A # of 256×8 ROMs : 32, type of decoder: 2×4 ROMs : 64, type of decoder : 3X8 cht of 256X8 ROMs : 32, type of decoder: 3X8 D # of 256×8 ROMs : 64, type of decoder: 6×64 \u00ae B. # of 256X8 Click Save and Submit to save and submit. Clhick Save All Answers to save all ansuens! search<\/p>\n\n\n\n
The Correct Answer and Explanation is:<\/mark><\/strong><\/p>\n\n\n\n\n\n\n\n
QUESTION 4<\/strong><\/h3>\n\n\n\n
Question:<\/strong> How many 256×8 ROMs are needed to make a 4096×8 ROM, and what kind of decoder should be used?<\/p>\n\n\n\n
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A 256×8 ROM has 256 addresses, each storing 8 bits.<\/li>\n\n\n\n
A 4096×8 ROM requires 4096 addresses, each storing 8 bits.<\/li>\n<\/ul>\n\n\n\n
So, we need: 4096256=16 ROMs\\frac{4096}{256} = 16 \\text{ ROMs}<\/p>\n\n\n\n
To select among 16 ROMs, we need a decoder that takes 4 input lines and activates one of the 16 output lines. That means a 4-to-16 decoder<\/strong> is required.<\/p>\n\n\n\n
\u2705 Correct Answer: D \u2014 16 ROMs and a 4×16 decoder<\/strong><\/p>\n\n\n\n\n\n\n\n
QUESTION 5<\/strong><\/h3>\n\n\n\n
Question:<\/strong> To compose a 4096×1 multiplexer using only 8×1 multiplexers, how many select inputs are needed and how many 8×1 muxes are needed?<\/p>\n\n\n\n
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A 4096×1 mux selects 1 of 4096 inputs.<\/li>\n\n\n\n
To address 2048 words, you need a decoder to select among 8 blocks (2048\/256 = 8): log\u20612(8)=3\u21d23×8 decoder\\log_2(8) = 3 \\Rightarrow \\text{3×8 decoder}<\/p>\n\n\n\n
\u2705 Correct Answer: B \u2014 64 ROMs and a 3×8 decoder<\/strong><\/p>\n\n\n\n\n\n\n\n
Final Answers Summary<\/strong>:<\/h3>\n\n\n\n
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Q4:<\/strong> D \u2014 16 ROMs, 4×16 decoder<\/li>\n\n\n\n
Q5:<\/strong> D \u2014 12 select inputs, 585 8×1 muxes<\/li>\n\n\n\n
Q6:<\/strong> B \u2014 64 ROMs, 3×8 decoder<\/li>\n<\/ul>\n\n\n\n<\/figure>\n","protected":false},"excerpt":{"rendered":"
QUESTION 4 4. How many 256X8 ROMs are needed to make a 4096×8 ROM and what kind of decoder should be used? (Use only 256X8 ROMs) A # of 256×8 ROMs : 4, type of decoder : 2×4 OB t of 256X8 ROMs : 8, type of decoder: 3X8 c, # of 256×8 ROMs : […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[25],"tags":[],"class_list":["post-222150","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/222150","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/comments?post=222150"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/222150\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=222150"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=222150"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=222150"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
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