{"id":23,"date":"2014-07-16T22:32:01","date_gmt":"2014-07-16T21:32:01","guid":{"rendered":"http:\/\/microdiscray.com\/?p=23"},"modified":"2014-07-16T23:39:02","modified_gmt":"2014-07-16T22:39:02","slug":"the-design-part-2-the-alu","status":"publish","type":"post","link":"http:\/\/www.microdiscray.com\/?p=23","title":{"rendered":"The Design, Part 2: The ALU."},"content":{"rendered":"<p>I have nearly completed the initial design of the ALU.<\/p>\n<p>There are still some bits missing, and I havent simulated the whole ALU yet, only partly att block-level<\/p>\n<p>It will support the following primitive functions:<\/p>\n<ul>\n<li>AND<\/li>\n<li>OR<\/li>\n<li>NOR<\/li>\n<li>XOR<\/li>\n<li>ADD<\/li>\n<li>SUB<\/li>\n<li>SLT<\/li>\n<\/ul>\n<p>Here is a screenshot of the ALU<\/p>\n<p><a href=\"http:\/\/microdiscray.com\/wp-content\/uploads\/2014\/07\/Schematic-Editor-Circuit-_-1-BIT_ALU-Page-_-MAINPAGE-Project-_-ECL-Page-_-1.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-24\" src=\"http:\/\/microdiscray.com\/wp-content\/uploads\/2014\/07\/Schematic-Editor-Circuit-_-1-BIT_ALU-Page-_-MAINPAGE-Project-_-ECL-Page-_-1-300x212.jpg\" alt=\"Schematic Editor ( Circuit _ 1-BIT_ALU - Page _ MAINPAGE ) [Project _ ECL] Page _ 1\" width=\"300\" height=\"212\" srcset=\"http:\/\/www.microdiscray.com\/wp-content\/uploads\/2014\/07\/Schematic-Editor-Circuit-_-1-BIT_ALU-Page-_-MAINPAGE-Project-_-ECL-Page-_-1-300x212.jpg 300w, http:\/\/www.microdiscray.com\/wp-content\/uploads\/2014\/07\/Schematic-Editor-Circuit-_-1-BIT_ALU-Page-_-MAINPAGE-Project-_-ECL-Page-_-1-1024x723.jpg 1024w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><\/p>\n<p>And the more readable pdf-file <a href=\"http:\/\/microdiscray.com\/wp-content\/uploads\/2014\/07\/Schematic-Editor-Circuit-_-1-BIT_ALU-Page-_-MAINPAGE-Project-_-ECL-Page-_-1.pdf\">Main ALU<\/a><\/p>\n<p>There is also a register section, 3 registers (at the moment) one bit per slice.<\/p>\n<p><a href=\"http:\/\/microdiscray.com\/wp-content\/uploads\/2014\/07\/Schematic-Editor-Circuit-_-1-BIT_ALU-Page-_-REG-Project-_-ECL-Page-_-1.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-26\" src=\"http:\/\/microdiscray.com\/wp-content\/uploads\/2014\/07\/Schematic-Editor-Circuit-_-1-BIT_ALU-Page-_-REG-Project-_-ECL-Page-_-1-300x212.jpg\" alt=\"Schematic Editor ( Circuit _ 1-BIT_ALU - Page _ REG ) [Project _ ECL] Page _ 1\" width=\"300\" height=\"212\" srcset=\"http:\/\/www.microdiscray.com\/wp-content\/uploads\/2014\/07\/Schematic-Editor-Circuit-_-1-BIT_ALU-Page-_-REG-Project-_-ECL-Page-_-1-300x212.jpg 300w, http:\/\/www.microdiscray.com\/wp-content\/uploads\/2014\/07\/Schematic-Editor-Circuit-_-1-BIT_ALU-Page-_-REG-Project-_-ECL-Page-_-1-1024x723.jpg 1024w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><\/p>\n<p>The pdf: <a href=\"http:\/\/microdiscray.com\/wp-content\/uploads\/2014\/07\/Schematic-Editor-Circuit-_-1-BIT_ALU-Page-_-REG-Project-_-ECL-Page-_-1.pdf\">Registers<\/a><\/p>\n<p>There is three register A, B and Result.<br \/>\nthe registers consist of\u00a0one D Flip-Flop, per gate together with demultiplexers for selecting the function<\/p>\n<p>The following operations is supported, it probably will be changed in the future:<\/p>\n<ul>\n<li>CPYMA (copy from Data-bus to A)<\/li>\n<li>CPYMB<\/li>\n<li>CPYRM ( Copy Result to Data-bus)<\/li>\n<li>CPYRA (Copy Result to A)<\/li>\n<li>CPYRB<\/li>\n<\/ul>\n<p>When you look at the schematics, it might be a Little bit strange, but using ECL has an advantage compared to other families, The complementary output is easily accessible, which means that I can use that to reduce the number of gates needed.<\/p>\n<p>For example, if I need an 2-input AND-Gate, you will use two inverters on the input of a NOR-Gate, thus, using the inverted output off the previous gate, instead of the normal output, I can omitt the inverters, saving two gates (Three transistors per gate).<\/p>\n<p>This is basically what will go on each ALU-Slice Circuit board, together with the Biasing Circuit (I am also playing with the Idea of having a common Bias Circuit for the whole computer).<\/p>\n<p>Apart from the above, there will also be a separate PCB for Look-Ahead Carry, as well as status register and Zero detecting Circuit.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>I have nearly completed the initial design of the ALU. There are still some bits missing, and I havent simulated the whole ALU yet, only partly att block-level It will support the following primitive functions: AND OR NOR XOR ADD SUB SLT Here is a screenshot of the ALU And the more readable pdf-file Main [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9,1],"tags":[],"class_list":["post-23","post","type-post","status-publish","format-standard","hentry","category-design","category-uncategorized"],"_links":{"self":[{"href":"http:\/\/www.microdiscray.com\/index.php?rest_route=\/wp\/v2\/posts\/23","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.microdiscray.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.microdiscray.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.microdiscray.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.microdiscray.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=23"}],"version-history":[{"count":4,"href":"http:\/\/www.microdiscray.com\/index.php?rest_route=\/wp\/v2\/posts\/23\/revisions"}],"predecessor-version":[{"id":29,"href":"http:\/\/www.microdiscray.com\/index.php?rest_route=\/wp\/v2\/posts\/23\/revisions\/29"}],"wp:attachment":[{"href":"http:\/\/www.microdiscray.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=23"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.microdiscray.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=23"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.microdiscray.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=23"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}