{"id":50,"date":"2004-04-15T23:33:08","date_gmt":"2004-04-16T07:33:08","guid":{"rendered":"\/?p=50"},"modified":"2004-04-15T23:33:08","modified_gmt":"2004-04-16T07:33:08","slug":"who-wants-to-kick-an-ass","status":"publish","type":"post","link":"https:\/\/tim.cexx.org\/?p=50","title":{"rendered":"Who wants to kick an ass?"},"content":{"rendered":"

I do, I do! After spending weeks intermittently puzzling over sporadic, but semi-deterministic odd behaviors on the chip I was hacking firmware for at work (you know, like return<\/u> instructions that didn’t return<\/u>), and throwing in "good-luck NOP<\/a>s" until mysterious problems just as mysteriously went away (and hoping they didn’t return), I go and manage to dig up an errata sheet<\/a> and find the following: <\/p>\n

Certain code sequence and placement may cause
\nthe corruption of a few bits in the instruction fetch
\nwhen the part is used above 4 MHz. A corrupted
\ninstruction fetch will cause the part to execute an
\nimproper instruction and result in unpredictable
\noutputs.<\/p>\n

Microchip cannot predict which code sequences
\nand placement will cause this failure. If this failure
\nmechanism exists in your system, it should be
\nevident during statistically significant preproduction
\ntesting (minimum suggested sample
\nsize 100 units) of your particular code sequence and placement.<\/tt><\/p>\n

Yeah, that’s nice and helpful. Umm…we have *2* units.<\/sub> (How do products like this make it out the door?) Anyway, if my travels ever take me near Microchip Systems HQ, I am planning a free seminar on embedded systems<\/a>. (Umm…Title will be ‘Innovative boot-up procedures’)<\/p>\n

\nQOTD: “I recently saw a distraught young lady weeping beside her car. “Do you
\nneed some help?” I asked. She replied, “I knew I should have replaced the battery to this remote door unlocker. Now I can’t get into my car. Do you think they (pointing to a distant convenient store) would have a battery to fit this?” “Hmmm, I dunno. Do you have an alarm too?” I asked. “No, just this remote thingy,” she answered, handing it and the car keys to me. As I took the key and manually unlocked the door, I replied, “Why don’t you drive over there and check about the batteries–it’s a long walk.”<\/p>\n","protected":false},"excerpt":{"rendered":"

I do, I do! After spending weeks intermittently puzzling over sporadic, but semi-deterministic odd behaviors on the chip I was hacking firmware for at work (you know, like return instructions that didn’t return), and throwing in "good-luck NOPs" until mysterious problems just as mysteriously went away (and hoping they didn’t return), I go and manage […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_FSMCFIC_featured_image_caption":"","_FSMCFIC_featured_image_nocaption":"","_FSMCFIC_featured_image_hide":"","iawp_total_views":7,"footnotes":""},"categories":[1],"tags":[],"class_list":["post-50","post","type-post","status-publish","format-standard","hentry","category-general"],"_links":{"self":[{"href":"https:\/\/tim.cexx.org\/index.php?rest_route=\/wp\/v2\/posts\/50","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/tim.cexx.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/tim.cexx.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/tim.cexx.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/tim.cexx.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=50"}],"version-history":[{"count":0,"href":"https:\/\/tim.cexx.org\/index.php?rest_route=\/wp\/v2\/posts\/50\/revisions"}],"wp:attachment":[{"href":"https:\/\/tim.cexx.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=50"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/tim.cexx.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=50"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/tim.cexx.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=50"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}