{"id":16,"date":"2020-02-15T20:08:19","date_gmt":"2020-02-15T20:08:19","guid":{"rendered":"http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s20-teamc0\/?p=16"},"modified":"2020-02-29T19:28:13","modified_gmt":"2020-02-29T19:28:13","slug":"adolfos-status-update-for-2-15-2020","status":"publish","type":"post","link":"http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s20-teamc0\/2020\/02\/15\/adolfos-status-update-for-2-15-2020\/","title":{"rendered":"Adolfo&#8217;s Status Update for 2\/15\/2020"},"content":{"rendered":"<p>This week I worked with the rest of the group on figuring out the CPU&#8217;s design. I found <a href=\"https:\/\/gekkio.fi\/files\/gb-docs\/gbctr.pdf\">this document<\/a> which gave accurate timings for each instruction (it is incomplete though as it is a work in progress). With it, we were able to draw a datapath we believe accurately represents the Gameboy&#8217;s pipeline. Afterwards, Tess and I tried to figure out implementation details of multi-cycle instructions. We decided to solve this problem with an FSM which would control the different stages of a multi-cycle instruction. The basic idea is to have the FSM divide each multi-cycle instruction into smaller single cycle instructions. We believe this behavior mimics the Gameboy&#8217;s behavior best because it has been observed in the emulator community that in the middle of a multi-cycle instructions flags get set multiple times.<\/p>\n<p>On my graphics work, I did some research on the inner workings of the Gameboy PPU. My next action item based on this will be to sketch out a datapath for it so that we can talk about it in the design review and also so I can get started with implementing it. Furthermore, I got the VGA controller working and tested it on the screens in the labs. It has a small bug with the bottom line of the display, I will try to figure it out sometime this week, but it&#8217;s not a priority. One thing that I will have to figure out is how to display the Gameboi&#8217;s output since the resolution doesn&#8217;t match the 640&#215;480 resolution of the lab&#8217;s screens. I was thinking of probably having a pixel in the original Gameboy&#8217;s screen represent multiple pixels on the screen. This is a discussion for the future.<\/p>\n<p>Action items for next report:<\/p>\n<ul>\n<li>Make a PPU datapath drawing<\/li>\n<li>Get the Gameboi decoder and datapath implemented<\/li>\n<li>Fix the VGA glitch<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>This week I worked with the rest of the group on figuring out the CPU&#8217;s design. I found this document which gave accurate timings for each instruction (it is incomplete though as it is a work in progress). With it, we were able to draw a datapath we believe accurately represents the Gameboy&#8217;s pipeline. Afterwards, &hellip; <a href=\"http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s20-teamc0\/2020\/02\/15\/adolfos-status-update-for-2-15-2020\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Adolfo&#8217;s Status Update for 2\/15\/2020&#8221;<\/span><\/a><\/p>\n","protected":false},"author":275,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[4],"tags":[],"_links":{"self":[{"href":"http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s20-teamc0\/wp-json\/wp\/v2\/posts\/16"}],"collection":[{"href":"http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s20-teamc0\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s20-teamc0\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s20-teamc0\/wp-json\/wp\/v2\/users\/275"}],"replies":[{"embeddable":true,"href":"http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s20-teamc0\/wp-json\/wp\/v2\/comments?post=16"}],"version-history":[{"count":2,"href":"http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s20-teamc0\/wp-json\/wp\/v2\/posts\/16\/revisions"}],"predecessor-version":[{"id":34,"href":"http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s20-teamc0\/wp-json\/wp\/v2\/posts\/16\/revisions\/34"}],"wp:attachment":[{"href":"http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s20-teamc0\/wp-json\/wp\/v2\/media?parent=16"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s20-teamc0\/wp-json\/wp\/v2\/categories?post=16"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s20-teamc0\/wp-json\/wp\/v2\/tags?post=16"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}