{"id":1698,"date":"2022-10-23T18:35:42","date_gmt":"2022-10-23T22:35:42","guid":{"rendered":"https:\/\/blogs.sw.siemens.com\/tessent\/?p=1698"},"modified":"2026-03-26T16:06:55","modified_gmt":"2026-03-26T20:06:55","slug":"how-to-master-dft-for-tile-based-designs","status":"publish","type":"post","link":"https:\/\/blogs.sw.siemens.com\/tessent\/2022\/10\/23\/how-to-master-dft-for-tile-based-designs\/","title":{"rendered":"How to master DFT for tile-based designs"},"content":{"rendered":"\n<p style=\"font-size:18px\">Tile-based IC design flows are predominant in today\u2019s chips. A tiling style affects design-for-test (DFT) and calls for special attention to handling how scan channels are distributed across tiles. Tessent products can support tile-based designs from boundary scan, IJTAG and memory BISR chain routing, Streaming Scan Network, and scan retargeting. DFT for tile-based designs was a hot topic at Siemens User2User meeting this year, and now the video of Vidya Neerkundar describing it is available to view on demand.<\/p>\n\n\n\n<div class=\"wp-block-buttons is-layout-flex wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button\"><a class=\"wp-block-button__link\" href=\"https:\/\/resources.sw.siemens.com\/en-US\/video-dft-for-tile-based-designs\" target=\"_blank\" rel=\"noreferrer noopener\">Watch the video<\/a><\/div>\n<\/div>\n\n\n\n<p>Take this example tiled design with 3 unique tiles. C1 and C2 are mirrored on either side of C3. The physical blocks are abutted and there is no logic at the chip level.<\/p>\n\n\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:100%\"><div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium\"><img loading=\"lazy\" decoding=\"async\" width=\"600\" height=\"338\" src=\"https:\/\/blogs.sw.siemens.com\/wp-content\/uploads\/sites\/48\/2022\/10\/tile-based-design-600x338.jpg\" alt=\"tile-based designs need special DFT support\" class=\"wp-image-1702\" srcset=\"https:\/\/blogs.sw.siemens.com\/wp-content\/uploads\/sites\/48\/2022\/10\/tile-based-design-600x338.jpg 600w, https:\/\/blogs.sw.siemens.com\/wp-content\/uploads\/sites\/48\/2022\/10\/tile-based-design-1024x577.jpg 1024w, https:\/\/blogs.sw.siemens.com\/wp-content\/uploads\/sites\/48\/2022\/10\/tile-based-design-768x433.jpg 768w, https:\/\/blogs.sw.siemens.com\/wp-content\/uploads\/sites\/48\/2022\/10\/tile-based-design-395x222.jpg 395w, https:\/\/blogs.sw.siemens.com\/wp-content\/uploads\/sites\/48\/2022\/10\/tile-based-design-900x507.jpg 900w, https:\/\/blogs.sw.siemens.com\/wp-content\/uploads\/sites\/48\/2022\/10\/tile-based-design.jpg 1166w\" sizes=\"auto, (max-width: 600px) 100vw, 600px\" \/><\/figure><\/div><\/div>\n<\/div>\n\n\n\n<p> The DFT approach to a tiled design like this would be:<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>Use hierarchical design flow<\/li><li>Top-level floor planning<\/li><li>Streaming Scan Network (SSN) for logic testing<\/li><li>Clocking: insert on-chip clock controller (OCC) in each tile<\/li><li>IJTAG, memory BIST, built-in self-repair (BISR) for tile-based designs<\/li><li>Embedded boundary scan and Boundary Scan Description Language (BSDL) extraction at chip-level<\/li><\/ul>\n\n\n\n<p>So how do you access the logic inside the tiles for testing? There are some challenges. Tiles will need varying numbers of input and output channels for compression, how do you allocate and route the chip IO pins to these channels? Can you efficiently broadcast data to identical tiles? How do you balance pipeline stages from chip IO pins to the channels?<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Tessent Streaming Scan Network (SSN) is key to DFT for tile-based designs<\/h3>\n\n\n\n<p>A fundamental requirement in testing tile-based designs is the need for test compression with an access mechanism like a bus to transfer packetized test data, which is what Tessent Streaming Scan Network (SNN) does.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/blogs.sw.siemens.com\/wp-content\/uploads\/sites\/48\/2022\/10\/SSN-web-image-1280x720-1-600x340.jpg\" alt=\"Tessent SSN supports DFT for tile-based chip designs\" class=\"wp-image-1705\" width=\"515\" height=\"293\" srcset=\"https:\/\/blogs.sw.siemens.com\/wp-content\/uploads\/sites\/48\/2022\/10\/SSN-web-image-1280x720-1-600x340.jpg 600w, https:\/\/blogs.sw.siemens.com\/wp-content\/uploads\/sites\/48\/2022\/10\/SSN-web-image-1280x720-1-1024x580.jpg 1024w, https:\/\/blogs.sw.siemens.com\/wp-content\/uploads\/sites\/48\/2022\/10\/SSN-web-image-1280x720-1-768x435.jpg 768w, https:\/\/blogs.sw.siemens.com\/wp-content\/uploads\/sites\/48\/2022\/10\/SSN-web-image-1280x720-1-1536x870.jpg 1536w, https:\/\/blogs.sw.siemens.com\/wp-content\/uploads\/sites\/48\/2022\/10\/SSN-web-image-1280x720-1-2048x1160.jpg 2048w, https:\/\/blogs.sw.siemens.com\/wp-content\/uploads\/sites\/48\/2022\/10\/SSN-web-image-1280x720-1-900x510.jpg 900w\" sizes=\"auto, (max-width: 515px) 100vw, 515px\" \/><\/figure><\/div>\n\n\n<p>SSN was designed to distribute scan data across abutted tiles. The uniform bus travels the chip in a plug and play manner\u2014there is no need to plan requirements for each tile up front. Using SSN can cut DFT development time in half. It lets designers decouple the core and chip level DFT and define the core grouping at retargeting time. Routing and timing closure is easier because it eliminates top-level muxing. SSN also reduces test time and test volume by up to 4X because:<\/p>\n\n\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:100%\">\n<ul class=\"wp-block-list\"><li>Packets are 100% scan data payload<\/li><li>There is less need for padding in test data<\/li><li>Core compression is optimal<\/li><li>Time multiplexing<\/li><li>Identical cores are tested at constant cost, with diagnosis support<\/li><\/ul>\n<\/div>\n<\/div>\n\n\n\n<p><\/p>\n\n\n\n<p><\/p>\n\n\n\n<p>The flexible, adaptable, and silicon-proven SSN is quickly becoming a fundamental solution for the DFT demands of today and tomorrow.\u00a0<\/p>\n\n\n\n<p><a href=\"https:\/\/resources.sw.siemens.com\/en-US\/video-dft-for-tile-based-designs\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>Watch the video<\/strong><\/a> for details on the DFT flow for tile-based designs, including clocking, inserting IJTAG, memory BIST and BISR, inserting boundary scan and BSDL extraction, creating DFT ports on tiles and connections between tiles, and simulation views of tiles.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Hierarchical designs that are tile-based or abutment based physical blocks are predominant in today\u2019s chips. Having no logic present at the chip-level calls for new approaches to testing these tile-based architectures. How a design for test (DFT) architecture can support tile-based designs is the focus of this presentation from U2U 2022.<\/p>\n","protected":false},"author":71644,"featured_media":1744,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"spanish_translation":"","french_translation":"","german_translation":"","italian_translation":"","polish_translation":"","japanese_translation":"","chinese_translation":"","footnotes":""},"categories":[11,7,1],"tags":[320,700,699],"industry":[53,56],"product":[269,683],"coauthors":[375],"class_list":["post-1698","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-video","category-learning-resources","category-news","tag-design-for-test","tag-ssn","tag-tile-based","industry-electronics-semiconductors","industry-semiconductor-devices","product-tessent","product-tessent-test"],"featured_image_url":"https:\/\/blogs.sw.siemens.com\/wp-content\/uploads\/sites\/48\/2022\/10\/u2u-tile-based-dft-scaled.jpg","_links":{"self":[{"href":"https:\/\/blogs.sw.siemens.com\/tessent\/wp-json\/wp\/v2\/posts\/1698","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.sw.siemens.com\/tessent\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.sw.siemens.com\/tessent\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.sw.siemens.com\/tessent\/wp-json\/wp\/v2\/users\/71644"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.sw.siemens.com\/tessent\/wp-json\/wp\/v2\/comments?post=1698"}],"version-history":[{"count":5,"href":"https:\/\/blogs.sw.siemens.com\/tessent\/wp-json\/wp\/v2\/posts\/1698\/revisions"}],"predecessor-version":[{"id":1746,"href":"https:\/\/blogs.sw.siemens.com\/tessent\/wp-json\/wp\/v2\/posts\/1698\/revisions\/1746"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blogs.sw.siemens.com\/tessent\/wp-json\/wp\/v2\/media\/1744"}],"wp:attachment":[{"href":"https:\/\/blogs.sw.siemens.com\/tessent\/wp-json\/wp\/v2\/media?parent=1698"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.sw.siemens.com\/tessent\/wp-json\/wp\/v2\/categories?post=1698"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.sw.siemens.com\/tessent\/wp-json\/wp\/v2\/tags?post=1698"},{"taxonomy":"industry","embeddable":true,"href":"https:\/\/blogs.sw.siemens.com\/tessent\/wp-json\/wp\/v2\/industry?post=1698"},{"taxonomy":"product","embeddable":true,"href":"https:\/\/blogs.sw.siemens.com\/tessent\/wp-json\/wp\/v2\/product?post=1698"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/blogs.sw.siemens.com\/tessent\/wp-json\/wp\/v2\/coauthors?post=1698"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}