{"id":139,"date":"2016-05-10T00:51:33","date_gmt":"2016-05-10T00:51:33","guid":{"rendered":"http:\/\/sites.nyuad.nyu.edu\/dfx\/?page_id=139"},"modified":"2016-06-10T14:47:43","modified_gmt":"2016-06-10T14:47:43","slug":"design-for-testability","status":"publish","type":"page","link":"https:\/\/sites.nyuad.nyu.edu\/dfx\/research-topics\/design-for-testability\/","title":{"rendered":"Design-for-Testability"},"content":{"rendered":"<p>[et_pb_section admin_label=&#8221;section&#8221; background_color=&#8221;#6f9a48&#8243; inner_shadow=&#8221;on&#8221; fullwidth=&#8221;on&#8221; transparent_background=&#8221;off&#8221; allow_player_pause=&#8221;off&#8221; parallax=&#8221;off&#8221; parallax_method=&#8221;off&#8221; padding_mobile=&#8221;off&#8221; make_fullwidth=&#8221;off&#8221; use_custom_width=&#8221;off&#8221; width_unit=&#8221;on&#8221; make_equal=&#8221;off&#8221; use_custom_gutter=&#8221;off&#8221;][et_pb_fullwidth_header admin_label=&#8221;Fullwidth Header&#8221; title=&#8221;Design-for-Testability Techniques&#8221; background_layout=&#8221;dark&#8221; text_orientation=&#8221;left&#8221; header_fullscreen=&#8221;off&#8221; header_scroll_down=&#8221;off&#8221; parallax=&#8221;off&#8221; parallax_method=&#8221;off&#8221; content_orientation=&#8221;center&#8221; image_orientation=&#8221;center&#8221; custom_button_one=&#8221;off&#8221; button_one_letter_spacing=&#8221;0&#8243; button_one_use_icon=&#8221;default&#8221; button_one_icon_placement=&#8221;right&#8221; button_one_on_hover=&#8221;on&#8221; button_one_letter_spacing_hover=&#8221;0&#8243; custom_button_two=&#8221;off&#8221; button_two_letter_spacing=&#8221;0&#8243; button_two_use_icon=&#8221;default&#8221; button_two_icon_placement=&#8221;right&#8221; button_two_on_hover=&#8221;on&#8221; button_two_letter_spacing_hover=&#8221;0&#8243; subhead_font_size=&#8221;1px&#8221;] [\/et_pb_fullwidth_header][\/et_pb_section][et_pb_section admin_label=&#8221;section&#8221;][et_pb_row admin_label=&#8221;Row&#8221;][et_pb_column type=&#8221;4_4&#8243;][et_pb_text admin_label=&#8221;Text&#8221; background_layout=&#8221;light&#8221; text_orientation=&#8221;center&#8221; text_font_size=&#8221;20&#8243; use_border_color=&#8221;off&#8221; border_color=&#8221;#ffffff&#8221; border_style=&#8221;solid&#8221;]<\/p>\n<p style=\"text-align: center;\"><strong>OCD Architecture [<a href=\"https:\/\/sites.nyuad.nyu.edu\/dfx\/index.php\/publications\/\">c27<\/a>, <a href=\"https:\/\/sites.nyuad.nyu.edu\/dfx\/index.php\/publications\/\">c28<\/a>, <a href=\"https:\/\/sites.nyuad.nyu.edu\/dfx\/index.php\/publications\/\">c32<\/a>, <a href=\"https:\/\/sites.nyuad.nyu.edu\/dfx\/index.php\/publications\/\">j13<\/a>, <a href=\"https:\/\/sites.nyuad.nyu.edu\/dfx\/index.php\/publications\/\">j14<\/a>, <a href=\"https:\/\/sites.nyuad.nyu.edu\/dfx\/index.php\/publications\/\">j16<\/a>, <a href=\"https:\/\/sites.nyuad.nyu.edu\/dfx\/index.php\/publications\/\">j27<\/a>, <a href=\"https:\/\/sites.nyuad.nyu.edu\/dfx\/index.php\/publications\/\">j28<\/a>, <a href=\"https:\/\/sites.nyuad.nyu.edu\/dfx\/index.php\/patents\/\">p1<\/a>, <a href=\"https:\/\/sites.nyuad.nyu.edu\/dfx\/index.php\/patents\/\">p2<\/a>, <a href=\"https:\/\/sites.nyuad.nyu.edu\/dfx\/index.php\/patents\/\">p3<\/a>]<br \/>\n<\/strong><\/p>\n<p>[\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row admin_label=&#8221;row&#8221;][et_pb_column type=&#8221;1_2&#8243;][et_pb_text admin_label=&#8221;Text&#8221; background_layout=&#8221;light&#8221; text_orientation=&#8221;left&#8221; use_border_color=&#8221;off&#8221; border_color=&#8221;#ffffff&#8221; border_style=&#8221;solid&#8221;]<\/p>\n<p>Ever increasing test costs along with time-to-market pressures necessitate aggressive Design-for-Testability (DfT) solutions that are compliant with the existing design flow. We have developed of add-on blocks to be integrated into the conventional compression-based scan architecture, providing DfT engineers ultimate <em>control <\/em>over <strong>O<\/strong>bservation of compacted test responses, <strong>C<\/strong>ontrollability of test stimuli through the decompressor, and <strong>D<\/strong>issipation of power during test. We refer to the proposed architecture as the <strong>OCD<\/strong> architecture.<\/p>\n<p>The first additional component, which we refer to as <em>Align-Encode<\/em>, is to be inserted between the scan input channels and the stimulus decompressor. Align-Encode is controlled directly to manipulate the care bit distribution of a test pattern in such a way that the pattern becomes encodable by the decompressor being utilized in the scan architecture, improving the compression ratio. The exact manipulation of the care bit distribution for a given pattern is determined through algorithms customized with respect to the decompressor. Refer to our papers <a href=\"https:\/\/sites.nyuad.nyu.edu\/dfx\/index.php\/publications\/\">c28<\/a> and <a href=\"https:\/\/sites.nyuad.nyu.edu\/dfx\/index.php\/publications\/\">j13<\/a>, or patent <a href=\"https:\/\/sites.nyuad.nyu.edu\/dfx\/index.php\/patents\/\">p1<\/a> for more information.<\/p>\n<p>The second additional component in the proposed architecture is <em>X-align<\/em>, which is to be inserted between the scan chain outputs and the response compactor. X-align is controlled directly to manipulate the distribution of the response x\u2019s with the goal of minimizing the corruption impact of these x\u2019s on the other response bits, improving scan cell observability through the compactor. The manipulation of x distribution has been mapped to the maximum satisfiability problem. Refer to our papers <a href=\"https:\/\/sites.nyuad.nyu.edu\/dfx\/index.php\/publications\/\">c32,<\/a> <a href=\"https:\/\/sites.nyuad.nyu.edu\/dfx\/index.php\/publications\/\">j16<\/a> and <a href=\"https:\/\/sites.nyuad.nyu.edu\/dfx\/index.php\/publications\/\">j28<\/a>, or patent <a href=\"https:\/\/sites.nyuad.nyu.edu\/dfx\/index.php\/patents\/\">p3<\/a> for more information.<\/p>\n<p>The third additional component in the proposed architecture is the dynamic partition block <em>Clock-Align<\/em>, which manipulates the scan chain clocks, and thus dynamically partitions scan chains in order to minimize peak power dissipation during test. Refer to our papers <a href=\"https:\/\/sites.nyuad.nyu.edu\/dfx\/index.php\/publications\/\">c27,<\/a> <a href=\"https:\/\/sites.nyuad.nyu.edu\/dfx\/index.php\/publications\/\">j14<\/a> and <a href=\"https:\/\/sites.nyuad.nyu.edu\/dfx\/index.php\/publications\/\">j27<\/a>, or patent <a href=\"https:\/\/sites.nyuad.nyu.edu\/dfx\/index.php\/patents\/\">p2 <\/a>for more information.<\/p>\n<p>The proposed add-on blocks and the associated CAD tools can be seamlessly integrated into the existing design flow, providing a practical yet powerful platform for leashing test costs.<\/p>\n<p>[\/et_pb_text][\/et_pb_column][et_pb_column type=&#8221;1_2&#8243;][et_pb_image admin_label=&#8221;OCD Architecture Image&#8221; src=&#8221;https:\/\/sites.nyuad.nyu.edu\/dfx\/wp-content\/uploads\/2016\/05\/OCD-1.png&#8221; alt=&#8221;OCD Architecture&#8221; title_text=&#8221;OCD Architecture&#8221; show_in_lightbox=&#8221;off&#8221; url_new_window=&#8221;off&#8221; use_overlay=&#8221;off&#8221; animation=&#8221;off&#8221; sticky=&#8221;off&#8221; align=&#8221;left&#8221; force_fullwidth=&#8221;off&#8221; always_center_on_mobile=&#8221;on&#8221; use_border_color=&#8221;off&#8221; border_color=&#8221;#ffffff&#8221; border_style=&#8221;solid&#8221;] [\/et_pb_image][et_pb_image admin_label=&#8221;align encode Image&#8221; src=&#8221;https:\/\/sites.nyuad.nyu.edu\/dfx\/wp-content\/uploads\/2016\/05\/align-encode.png&#8221; alt=&#8221;align encode&#8221; title_text=&#8221;align encode&#8221; show_in_lightbox=&#8221;off&#8221; url_new_window=&#8221;off&#8221; use_overlay=&#8221;off&#8221; animation=&#8221;off&#8221; sticky=&#8221;off&#8221; align=&#8221;left&#8221; force_fullwidth=&#8221;off&#8221; always_center_on_mobile=&#8221;on&#8221; use_border_color=&#8221;off&#8221; border_color=&#8221;#ffffff&#8221; border_style=&#8221;solid&#8221;] [\/et_pb_image][et_pb_image admin_label=&#8221;x align Image&#8221; src=&#8221;https:\/\/sites.nyuad.nyu.edu\/dfx\/wp-content\/uploads\/2016\/05\/x-align.png&#8221; alt=&#8221;x align&#8221; title_text=&#8221;x align&#8221; show_in_lightbox=&#8221;off&#8221; url_new_window=&#8221;off&#8221; use_overlay=&#8221;off&#8221; animation=&#8221;off&#8221; sticky=&#8221;off&#8221; align=&#8221;left&#8221; force_fullwidth=&#8221;off&#8221; always_center_on_mobile=&#8221;on&#8221; use_border_color=&#8221;off&#8221; border_color=&#8221;#ffffff&#8221; border_style=&#8221;solid&#8221;] [\/et_pb_image][\/et_pb_column][\/et_pb_row][et_pb_row admin_label=&#8221;Row&#8221;][et_pb_column type=&#8221;4_4&#8243;][et_pb_divider admin_label=&#8221;Divider&#8221; color=&#8221;#6f9a48&#8243; show_divider=&#8221;on&#8221; divider_style=&#8221;solid&#8221; divider_position=&#8221;top&#8221; hide_on_mobile=&#8221;on&#8221;] [\/et_pb_divider][\/et_pb_column][\/et_pb_row][et_pb_row admin_label=&#8221;Row&#8221;][et_pb_column type=&#8221;4_4&#8243;][et_pb_text admin_label=&#8221;Text&#8221; background_layout=&#8221;light&#8221; text_orientation=&#8221;center&#8221; text_font_size=&#8221;20&#8243; use_border_color=&#8221;off&#8221; border_color=&#8221;#ffffff&#8221; border_style=&#8221;solid&#8221;]<\/p>\n<p style=\"text-align: center;\"><strong>Expedited Compact\u00a0 [<a href=\"https:\/\/sites.nyuad.nyu.edu\/dfx\/index.php\/publications\/\">c44<\/a>, <a href=\"https:\/\/sites.nyuad.nyu.edu\/dfx\/index.php\/publications\/\">j32<\/a>, <a href=\"https:\/\/sites.nyuad.nyu.edu\/dfx\/index.php\/patents\/\">p5<\/a>]<br \/>\n<\/strong><\/p>\n<p>[\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row admin_label=&#8221;Row&#8221;][et_pb_column type=&#8221;1_2&#8243;][et_pb_text admin_label=&#8221;Text&#8221; background_layout=&#8221;light&#8221; text_orientation=&#8221;left&#8221; use_border_color=&#8221;off&#8221; border_color=&#8221;#ffffff&#8221; border_style=&#8221;solid&#8221;]<\/p>\n<p>Excessive switching activity during scan operations endangers the reliability of the chip under test. We propose an architectural solution, which we refer to as <em>Expedited-Compact<\/em>, to mitigate the scan power problem that otherwise creates high heat dissipation and possibly hot spots. Expedited-Compact architecture advances the response compaction operations by utilizing scan chains (the top one in the example) as buffer. This enables the flushing of the transition-wise costly response data out of the system quickly, providing scan-out power savings.In this example, the response compaction operations are completed by the end of the first third of shift cycles; by that time, all the responses in the chains other than the buffer chain are replaced with constant 0&#8217;s.<\/p>\n<p>[\/et_pb_text][\/et_pb_column][et_pb_column type=&#8221;1_2&#8243;][et_pb_image admin_label=&#8221;EC architecture Image&#8221; src=&#8221;https:\/\/sites.nyuad.nyu.edu\/dfx\/wp-content\/uploads\/2016\/05\/EC-1.png&#8221; alt=&#8221;EC architecture&#8221; title_text=&#8221;EC architecture&#8221; show_in_lightbox=&#8221;off&#8221; url_new_window=&#8221;off&#8221; use_overlay=&#8221;off&#8221; animation=&#8221;off&#8221; sticky=&#8221;off&#8221; align=&#8221;left&#8221; force_fullwidth=&#8221;off&#8221; always_center_on_mobile=&#8221;on&#8221; use_border_color=&#8221;off&#8221; border_color=&#8221;#ffffff&#8221; border_style=&#8221;solid&#8221;] [\/et_pb_image][et_pb_text admin_label=&#8221;Text&#8221; background_layout=&#8221;light&#8221; text_orientation=&#8221;left&#8221; use_border_color=&#8221;off&#8221; border_color=&#8221;#ffffff&#8221; border_style=&#8221;solid&#8221;]<\/p>\n<p>Expedited compact architecture for 4 chains and 3 blocks. Refer to our papers <a href=\"https:\/\/sites.nyuad.nyu.edu\/dfx\/index.php\/publications\/\">c44<\/a> and <a href=\"https:\/\/sites.nyuad.nyu.edu\/dfx\/index.php\/publications\/\">j32<\/a>, or patent <a href=\"https:\/\/sites.nyuad.nyu.edu\/dfx\/index.php\/patents\/\">p5 <\/a>for more information.<\/p>\n<p>[\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row admin_label=&#8221;Row&#8221;][et_pb_column type=&#8221;4_4&#8243;][et_pb_text admin_label=&#8221;Text&#8221; background_layout=&#8221;light&#8221; text_orientation=&#8221;left&#8221; use_border_color=&#8221;off&#8221; border_color=&#8221;#ffffff&#8221; border_style=&#8221;solid&#8221;]<\/p>\n<p>The proposed DfT-based approach is non-intrusive for design flow, requires a very minor investment in area, and in turn delivers significant and predictable savings in test power. The proposed solution reduces average test power without resorting to x-filling, enabling the application of orthogonal x-filling techniques in conjunction.<\/p>\n<p>[\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row admin_label=&#8221;Row&#8221;][et_pb_column type=&#8221;4_4&#8243;][et_pb_divider admin_label=&#8221;Divider&#8221; color=&#8221;#6f9a48&#8243; show_divider=&#8221;on&#8221; divider_style=&#8221;solid&#8221; divider_position=&#8221;top&#8221; hide_on_mobile=&#8221;on&#8221;] [\/et_pb_divider][\/et_pb_column][\/et_pb_row][et_pb_row admin_label=&#8221;Row&#8221;][et_pb_column type=&#8221;4_4&#8243;][et_pb_text admin_label=&#8221;Text&#8221; background_layout=&#8221;light&#8221; text_orientation=&#8221;center&#8221; text_font_size=&#8221;20&#8243; use_border_color=&#8221;off&#8221; border_color=&#8221;#ffffff&#8221; border_style=&#8221;solid&#8221;]<\/p>\n<p style=\"text-align: center;\"><strong>Toggle-Based Masking\u00a0 [<a href=\"https:\/\/sites.nyuad.nyu.edu\/dfx\/index.php\/publications\/\">c49<\/a>, <a href=\"https:\/\/sites.nyuad.nyu.edu\/dfx\/index.php\/publications\/\">c61<\/a>, <a href=\"https:\/\/sites.nyuad.nyu.edu\/dfx\/index.php\/patents\/\">p8<\/a>]<br \/>\n<\/strong><\/p>\n<p>[\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row admin_label=&#8221;Row&#8221;][et_pb_column type=&#8221;1_2&#8243;][et_pb_text admin_label=&#8221;Text&#8221; background_layout=&#8221;light&#8221; text_orientation=&#8221;left&#8221; use_border_color=&#8221;off&#8221; border_color=&#8221;#ffffff&#8221; border_style=&#8221;solid&#8221;]<\/p>\n<p>Unknown response bits (x&#8217;s) exhibit a clustered distribution in responses due to structural proximity of x sources. We exploited this behavior and developed a toggle-based masking scheme that is capable of delivering very high observability levels in the case of clustered x distributions. Toggle-mask can be used for two purposes. In the first case, all the x&#8217;s can be masked along with a minimum number of known response bits (illustrated in the figure). The mask \/ no-mask decision is toggled in exactly one chain in any shift cycle. A clean MISR signature is produced at the expense of minimal observability (of known response bits) loss. In the second case, toggle-mask can be used as an x-filter that allows a certain number\/distribution of x&#8217;s to pass, in order to further improve the observability levels. Naturally, the proposed toggle-filter is to be paired with another technique, such as an x-canceling MISR, which is capable of canceling the x&#8217;s in the signature via post-processing operations. X-filter can adjust the number\/distribution of x in-flow into the MISR, delivering a perfect control over test time and observability. More information can be found in our papers <a href=\"https:\/\/sites.nyuad.nyu.edu\/dfx\/index.php\/publications\/\">c49<\/a> and <a href=\"https:\/\/sites.nyuad.nyu.edu\/dfx\/index.php\/publications\/\">c61<\/a>, or patent <a href=\"https:\/\/sites.nyuad.nyu.edu\/dfx\/index.php\/patents\/\">p8<\/a>.<\/p>\n<p>[\/et_pb_text][\/et_pb_column][et_pb_column type=&#8221;1_2&#8243;][et_pb_image admin_label=&#8221;toggle mask architecture Image&#8221; src=&#8221;https:\/\/sites.nyuad.nyu.edu\/dfx\/wp-content\/uploads\/2016\/05\/toggle-mask.png&#8221; alt=&#8221;toggle mask architecture&#8221; title_text=&#8221;toggle mask architecture&#8221; show_in_lightbox=&#8221;off&#8221; url_new_window=&#8221;off&#8221; use_overlay=&#8221;off&#8221; animation=&#8221;off&#8221; sticky=&#8221;off&#8221; align=&#8221;left&#8221; force_fullwidth=&#8221;off&#8221; always_center_on_mobile=&#8221;on&#8221; use_border_color=&#8221;off&#8221; border_color=&#8221;#ffffff&#8221; border_style=&#8221;solid&#8221;] [\/et_pb_image][et_pb_text admin_label=&#8221;Text&#8221; background_layout=&#8221;light&#8221; text_orientation=&#8221;left&#8221; use_border_color=&#8221;off&#8221; border_color=&#8221;#ffffff&#8221; border_style=&#8221;solid&#8221;]<\/p>\n<p>Example scan architecture with 7 chains. Toggle-mask eradicates all x&#8217;s while losing 9 known response bits.<\/p>\n<p>[\/et_pb_text][et_pb_image admin_label=&#8221;toggle masking architecture Image&#8221; src=&#8221;https:\/\/sites.nyuad.nyu.edu\/dfx\/wp-content\/uploads\/2016\/05\/toggle-mask-arch.png&#8221; alt=&#8221;toggle masking architecture&#8221; title_text=&#8221;toggle masking architecture&#8221; show_in_lightbox=&#8221;off&#8221; url_new_window=&#8221;off&#8221; use_overlay=&#8221;off&#8221; animation=&#8221;off&#8221; sticky=&#8221;off&#8221; align=&#8221;left&#8221; force_fullwidth=&#8221;off&#8221; always_center_on_mobile=&#8221;on&#8221; use_border_color=&#8221;off&#8221; border_color=&#8221;#ffffff&#8221; border_style=&#8221;solid&#8221;] [\/et_pb_image][et_pb_text admin_label=&#8221;Text&#8221; background_layout=&#8221;light&#8221; text_orientation=&#8221;left&#8221; use_border_color=&#8221;off&#8221; border_color=&#8221;#ffffff&#8221; border_style=&#8221;solid&#8221;]<\/p>\n<p>Masking decisions for one particular chain. Ideal masking; all x&#8217;s masked with no loss of any known bits.<\/p>\n<p>[\/et_pb_text][\/et_pb_column][\/et_pb_row][\/et_pb_section]<\/p>\n","protected":false},"excerpt":{"rendered":"<p>OCD Architecture [c27, c28, c32, j13, j14, j16, j27, j28, p1, p2, p3] Ever increasing test costs along with time-to-market pressures necessitate aggressive Design-for-Testability (DfT) solutions that are compliant with the existing design flow. We have developed of add-on blocks to be integrated into the conventional compression-based scan architecture, providing DfT engineers ultimate control over [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":125,"menu_order":3,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_et_pb_use_builder":"on","_et_pb_old_content":"","_et_gb_content_width":"","_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"footnotes":""},"class_list":["post-139","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/sites.nyuad.nyu.edu\/dfx\/wp-json\/wp\/v2\/pages\/139","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sites.nyuad.nyu.edu\/dfx\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/sites.nyuad.nyu.edu\/dfx\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/sites.nyuad.nyu.edu\/dfx\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/sites.nyuad.nyu.edu\/dfx\/wp-json\/wp\/v2\/comments?post=139"}],"version-history":[{"count":10,"href":"https:\/\/sites.nyuad.nyu.edu\/dfx\/wp-json\/wp\/v2\/pages\/139\/revisions"}],"predecessor-version":[{"id":514,"href":"https:\/\/sites.nyuad.nyu.edu\/dfx\/wp-json\/wp\/v2\/pages\/139\/revisions\/514"}],"up":[{"embeddable":true,"href":"https:\/\/sites.nyuad.nyu.edu\/dfx\/wp-json\/wp\/v2\/pages\/125"}],"wp:attachment":[{"href":"https:\/\/sites.nyuad.nyu.edu\/dfx\/wp-json\/wp\/v2\/media?parent=139"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}