forked from NVIDIA/open-gpu-doc
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathDCB-4.x-Specification.html
10010 lines (9926 loc) · 280 KB
/
DCB-4.x-Specification.html
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
<meta http-equiv="Content-Type" content="application/xhtml+xml; charset=UTF-8" />
<meta name="generator" content="AsciiDoc 8.6.8" />
<title>Device Control Block 4.x Specification</title>
<style type="text/css">
/* Shared CSS for AsciiDoc xhtml11 and html5 backends */
/* Default font. */
body {
font-family: Georgia,serif;
}
/* Title font. */
h1, h2, h3, h4, h5, h6,
div.title, caption.title,
thead, p.table.header,
#toctitle,
#author, #revnumber, #revdate, #revremark,
#footer {
font-family: Arial,Helvetica,sans-serif;
}
body {
margin: 1em 5% 1em 5%;
}
a {
color: blue;
text-decoration: underline;
}
a:visited {
color: fuchsia;
}
em {
font-style: italic;
color: navy;
}
strong {
font-weight: bold;
color: #083194;
}
h1, h2, h3, h4, h5, h6 {
color: #527bbd;
margin-top: 1.2em;
margin-bottom: 0.5em;
line-height: 1.3;
}
h1, h2, h3 {
border-bottom: 2px solid silver;
}
h2 {
padding-top: 0.5em;
}
h3 {
float: left;
}
h3 + * {
clear: left;
}
h5 {
font-size: 1.0em;
}
div.sectionbody {
margin-left: 0;
}
hr {
border: 1px solid silver;
}
p {
margin-top: 0.5em;
margin-bottom: 0.5em;
}
ul, ol, li > p {
margin-top: 0;
}
ul > li { color: #aaa; }
ul > li > * { color: black; }
.monospaced, code, pre {
font-family: "Courier New", Courier, monospace;
font-size: inherit;
color: navy;
padding: 0;
margin: 0;
}
#author {
color: #527bbd;
font-weight: bold;
font-size: 1.1em;
}
#email {
}
#revnumber, #revdate, #revremark {
}
#footer {
font-size: small;
border-top: 2px solid silver;
padding-top: 0.5em;
margin-top: 4.0em;
}
#footer-text {
float: left;
padding-bottom: 0.5em;
}
#footer-badges {
float: right;
padding-bottom: 0.5em;
}
#preamble {
margin-top: 1.5em;
margin-bottom: 1.5em;
}
div.imageblock, div.exampleblock, div.verseblock,
div.quoteblock, div.literalblock, div.listingblock, div.sidebarblock,
div.admonitionblock {
margin-top: 1.0em;
margin-bottom: 1.5em;
}
div.admonitionblock {
margin-top: 2.0em;
margin-bottom: 2.0em;
margin-right: 10%;
color: #606060;
}
div.content { /* Block element content. */
padding: 0;
}
/* Block element titles. */
div.title, caption.title {
color: #527bbd;
font-weight: bold;
text-align: left;
margin-top: 1.0em;
margin-bottom: 0.5em;
}
div.title + * {
margin-top: 0;
}
td div.title:first-child {
margin-top: 0.0em;
}
div.content div.title:first-child {
margin-top: 0.0em;
}
div.content + div.title {
margin-top: 0.0em;
}
div.sidebarblock > div.content {
background: #ffffee;
border: 1px solid #dddddd;
border-left: 4px solid #f0f0f0;
padding: 0.5em;
}
div.listingblock > div.content {
border: 1px solid #dddddd;
border-left: 5px solid #f0f0f0;
background: #f8f8f8;
padding: 0.5em;
}
div.quoteblock, div.verseblock {
padding-left: 1.0em;
margin-left: 1.0em;
margin-right: 10%;
border-left: 5px solid #f0f0f0;
color: #888;
}
div.quoteblock > div.attribution {
padding-top: 0.5em;
text-align: right;
}
div.verseblock > pre.content {
font-family: inherit;
font-size: inherit;
}
div.verseblock > div.attribution {
padding-top: 0.75em;
text-align: left;
}
/* DEPRECATED: Pre version 8.2.7 verse style literal block. */
div.verseblock + div.attribution {
text-align: left;
}
div.admonitionblock .icon {
vertical-align: top;
font-size: 1.1em;
font-weight: bold;
text-decoration: underline;
color: #527bbd;
padding-right: 0.5em;
}
div.admonitionblock td.content {
padding-left: 0.5em;
border-left: 3px solid #dddddd;
}
div.exampleblock > div.content {
border-left: 3px solid #dddddd;
padding-left: 0.5em;
}
div.imageblock div.content { padding-left: 0; }
span.image img { border-style: none; }
a.image:visited { color: white; }
dl {
margin-top: 0.8em;
margin-bottom: 0.8em;
}
dt {
margin-top: 0.5em;
margin-bottom: 0;
font-style: normal;
color: navy;
}
dd > *:first-child {
margin-top: 0.1em;
}
ul, ol {
list-style-position: outside;
}
ol.arabic {
list-style-type: decimal;
}
ol.loweralpha {
list-style-type: lower-alpha;
}
ol.upperalpha {
list-style-type: upper-alpha;
}
ol.lowerroman {
list-style-type: lower-roman;
}
ol.upperroman {
list-style-type: upper-roman;
}
div.compact ul, div.compact ol,
div.compact p, div.compact p,
div.compact div, div.compact div {
margin-top: 0.1em;
margin-bottom: 0.1em;
}
tfoot {
font-weight: bold;
}
td > div.verse {
white-space: pre;
}
div.hdlist {
margin-top: 0.8em;
margin-bottom: 0.8em;
}
div.hdlist tr {
padding-bottom: 15px;
}
dt.hdlist1.strong, td.hdlist1.strong {
font-weight: bold;
}
td.hdlist1 {
vertical-align: top;
font-style: normal;
padding-right: 0.8em;
color: navy;
}
td.hdlist2 {
vertical-align: top;
}
div.hdlist.compact tr {
margin: 0;
padding-bottom: 0;
}
.comment {
background: yellow;
}
.footnote, .footnoteref {
font-size: 0.8em;
}
span.footnote, span.footnoteref {
vertical-align: super;
}
#footnotes {
margin: 20px 0 20px 0;
padding: 7px 0 0 0;
}
#footnotes div.footnote {
margin: 0 0 5px 0;
}
#footnotes hr {
border: none;
border-top: 1px solid silver;
height: 1px;
text-align: left;
margin-left: 0;
width: 20%;
min-width: 100px;
}
div.colist td {
padding-right: 0.5em;
padding-bottom: 0.3em;
vertical-align: top;
}
div.colist td img {
margin-top: 0.3em;
}
@media print {
#footer-badges { display: none; }
}
#toc {
margin-bottom: 2.5em;
}
#toctitle {
color: #527bbd;
font-size: 1.1em;
font-weight: bold;
margin-top: 1.0em;
margin-bottom: 0.1em;
}
div.toclevel0, div.toclevel1, div.toclevel2, div.toclevel3, div.toclevel4 {
margin-top: 0;
margin-bottom: 0;
}
div.toclevel2 {
margin-left: 2em;
font-size: 0.9em;
}
div.toclevel3 {
margin-left: 4em;
font-size: 0.9em;
}
div.toclevel4 {
margin-left: 6em;
font-size: 0.9em;
}
span.aqua { color: aqua; }
span.black { color: black; }
span.blue { color: blue; }
span.fuchsia { color: fuchsia; }
span.gray { color: gray; }
span.green { color: green; }
span.lime { color: lime; }
span.maroon { color: maroon; }
span.navy { color: navy; }
span.olive { color: olive; }
span.purple { color: purple; }
span.red { color: red; }
span.silver { color: silver; }
span.teal { color: teal; }
span.white { color: white; }
span.yellow { color: yellow; }
span.aqua-background { background: aqua; }
span.black-background { background: black; }
span.blue-background { background: blue; }
span.fuchsia-background { background: fuchsia; }
span.gray-background { background: gray; }
span.green-background { background: green; }
span.lime-background { background: lime; }
span.maroon-background { background: maroon; }
span.navy-background { background: navy; }
span.olive-background { background: olive; }
span.purple-background { background: purple; }
span.red-background { background: red; }
span.silver-background { background: silver; }
span.teal-background { background: teal; }
span.white-background { background: white; }
span.yellow-background { background: yellow; }
span.big { font-size: 2em; }
span.small { font-size: 0.6em; }
span.underline { text-decoration: underline; }
span.overline { text-decoration: overline; }
span.line-through { text-decoration: line-through; }
div.unbreakable { page-break-inside: avoid; }
/*
* xhtml11 specific
*
* */
div.tableblock {
margin-top: 1.0em;
margin-bottom: 1.5em;
}
div.tableblock > table {
border: 3px solid #527bbd;
}
thead, p.table.header {
font-weight: bold;
color: #527bbd;
}
p.table {
margin-top: 0;
}
/* Because the table frame attribute is overriden by CSS in most browsers. */
div.tableblock > table[frame="void"] {
border-style: none;
}
div.tableblock > table[frame="hsides"] {
border-left-style: none;
border-right-style: none;
}
div.tableblock > table[frame="vsides"] {
border-top-style: none;
border-bottom-style: none;
}
/*
* html5 specific
*
* */
table.tableblock {
margin-top: 1.0em;
margin-bottom: 1.5em;
}
thead, p.tableblock.header {
font-weight: bold;
color: #527bbd;
}
p.tableblock {
margin-top: 0;
}
table.tableblock {
border-width: 3px;
border-spacing: 0px;
border-style: solid;
border-color: #527bbd;
border-collapse: collapse;
}
th.tableblock, td.tableblock {
border-width: 1px;
padding: 4px;
border-style: solid;
border-color: #527bbd;
}
table.tableblock.frame-topbot {
border-left-style: hidden;
border-right-style: hidden;
}
table.tableblock.frame-sides {
border-top-style: hidden;
border-bottom-style: hidden;
}
table.tableblock.frame-none {
border-style: hidden;
}
th.tableblock.halign-left, td.tableblock.halign-left {
text-align: left;
}
th.tableblock.halign-center, td.tableblock.halign-center {
text-align: center;
}
th.tableblock.halign-right, td.tableblock.halign-right {
text-align: right;
}
th.tableblock.valign-top, td.tableblock.valign-top {
vertical-align: top;
}
th.tableblock.valign-middle, td.tableblock.valign-middle {
vertical-align: middle;
}
th.tableblock.valign-bottom, td.tableblock.valign-bottom {
vertical-align: bottom;
}
/*
* manpage specific
*
* */
body.manpage h1 {
padding-top: 0.5em;
padding-bottom: 0.5em;
border-top: 2px solid silver;
border-bottom: 2px solid silver;
}
body.manpage h2 {
border-style: none;
}
body.manpage div.sectionbody {
margin-left: 3em;
}
@media print {
body.manpage div#toc { display: none; }
}
</style>
<script type="text/javascript">
/*<+'])');
// Function that scans the DOM tree for header elements (the DOM2
// nodeIterator API would be a better technique but not supported by all
// browsers).
var iterate = function (el) {
for (var i = el.firstChild; i != null; i = i.nextSibling) {
if (i.nodeType == 1 /* Node.ELEMENT_NODE */) {
var mo = re.exec(i.tagName);
if (mo && (i.getAttribute("class") || i.getAttribute("className")) != "float") {
result[result.length] = new TocEntry(i, getText(i), mo[1]-1);
}
iterate(i);
}
}
}
iterate(el);
return result;
}
var toc = document.getElementById("toc");
if (!toc) {
return;
}
// Delete existing TOC entries in case we're reloading the TOC.
var tocEntriesToRemove = [];
var i;
for (i = 0; i < toc.childNodes.length; i++) {
var entry = toc.childNodes[i];
if (entry.nodeName.toLowerCase() == 'div'
&& entry.getAttribute("class")
&& entry.getAttribute("class").match(/^toclevel/))
tocEntriesToRemove.push(entry);
}
for (i = 0; i < tocEntriesToRemove.length; i++) {
toc.removeChild(tocEntriesToRemove[i]);
}
// Rebuild TOC entries.
var entries = tocEntries(document.getElementById("content"), toclevels);
for (var i = 0; i < entries.length; ++i) {
var entry = entries[i];
if (entry.element.id == "")
entry.element.id = "_toc_" + i;
var a = document.createElement("a");
a.href = "#" + entry.element.id;
a.appendChild(document.createTextNode(entry.text));
var div = document.createElement("div");
div.appendChild(a);
div.className = "toclevel" + entry.toclevel;
toc.appendChild(div);
}
if (entries.length == 0)
toc.parentNode.removeChild(toc);
},
/////////////////////////////////////////////////////////////////////
// Footnotes generator
/////////////////////////////////////////////////////////////////////
/* Based on footnote generation code from:
* http://www.brandspankingnew.net/archive/2005/07/format_footnote.html
*/
footnotes: function () {
// Delete existing footnote entries in case we're reloading the footnodes.
var i;
var noteholder = document.getElementById("footnotes");
if (!noteholder) {
return;
}
var entriesToRemove = [];
for (i = 0; i < noteholder.childNodes.length; i++) {
var entry = noteholder.childNodes[i];
if (entry.nodeName.toLowerCase() == 'div' && entry.getAttribute("class") == "footnote")
entriesToRemove.push(entry);
}
for (i = 0; i < entriesToRemove.length; i++) {
noteholder.removeChild(entriesToRemove[i]);
}
// Rebuild footnote entries.
var cont = document.getElementById("content");
var spans = cont.getElementsByTagName("span");
var refs = {};
var n = 0;
for (i=0; i<spans.length; i++) {
if (spans[i].className == "footnote") {
n++;
var note = spans[i].getAttribute("data-note");
if (!note) {
// Use [\s\S] in place of . so multi-line matches work.
// Because JavaScript has no s (dotall) regex flag.
note = spans[i].innerHTML.match(/\s*\[([\s\S]*)]\s*/)[1];
spans[i].innerHTML =
"[<a id='_footnoteref_" + n + "' href='#_footnote_" + n +
"' title='View footnote' class='footnote'>" + n + "</a>]";
spans[i].setAttribute("data-note", note);
}
noteholder.innerHTML +=
"<div class='footnote' id='_footnote_" + n + "'>" +
"<a href='#_footnoteref_" + n + "' title='Return to text'>" +
n + "</a>. " + note + "</div>";
var id =spans[i].getAttribute("id");
if (id != null) refs["#"+id] = n;
}
}
if (n == 0)
noteholder.parentNode.removeChild(noteholder);
else {
// Process footnoterefs.
for (i=0; i<spans.length; i++) {
if (spans[i].className == "footnoteref") {
var href = spans[i].getElementsByTagName("a")[0].getAttribute("href");
href = href.match(/#.*/)[0]; // Because IE return full URL.
n = refs[href];
spans[i].innerHTML =
"[<a href='#_footnote_" + n +
"' title='View footnote' class='footnote'>" + n + "</a>]";
}
}
}
},
install: function(toclevels) {
var timerId;
function reinstall() {
asciidoc.footnotes();
if (toclevels) {
asciidoc.toc(toclevels);
}
}
function reinstallAndRemoveTimer() {
clearInterval(timerId);
reinstall();
}
timerId = setInterval(reinstall, 500);
if (document.addEventListener)
document.addEventListener("DOMContentLoaded", reinstallAndRemoveTimer, false);
else
window.onload = reinstallAndRemoveTimer;
}
}
asciidoc.install();
/*]]>*/
</script>
</head>
<body class="article">
<div id="header">
<h1>Device Control Block 4.x Specification</h1>
</div>
<div id="content">
<div class="sect1">
<h2 id="_purpose">Purpose</h2>
<div class="sectionbody">
<div class="paragraph"><p>Device Control Blocks (DCBs) are static tables used to describe the
board topology and connections external to the GPU chip.</p></div>
<div class="paragraph"><p>Each board built has specific additions to the capabilities through
external devices, as well as limitations where output lines are not
linked to device connectors. DCBs define the devices connected,
specific information needed to configure those devices, and the external
electrical connections such as HDMI and Display Port.</p></div>
<div class="paragraph"><p>DCBs do not try to explain the capabilities of the chip itself. That
information is implicit in the VBIOS, firmware and drivers, which are
built differently for each chip. Both the firmware and the drivers
know the inherent capability of each chip, and use runtime choices to
determine chip dependent code paths.</p></div>
<div class="ulist"><div class="title">DCB version and use</div><ul>
<li>
<p>
DCB 1.x is used with Core3 VBIOS (NV5, NV10, NV11, NV15, NV20).
</p>
</li>
<li>
<p>
DCB 2.x (2.0-2.4) is used with Core4 and Core4r2 VBIOS (NV17, NV25, NV28, NV3x).
</p>
</li>
<li>
<p>
DCB 3.0 is used with Core5 VBIOS (NV4x, G7x).
</p>
</li>
<li>
<p>
DCB 4.x is used with Core6, Core7, and Core8 VBIOS (G80+).
</p>
</li>
</ul></div>
<div class="sect2">
<h3 id="_dcb_4_1_changes">DCB 4.1 Changes</h3>
<div class="paragraph"><p>With the GM20x family of chips, any SOR could be used to drive any analog
pad link on the GPU. Using SORs and sublinks as fixed constants for a
DCB device entry no longer accurately described the board topology. To
fix this, DCB 4.1 repurposes the Output Resource Assignment Mask and
the Sublink Assignment Mask as a Pad Macro Assignment mask and a Pad
Link Assignment mask respectively for Digital Flat Panel Device Entries.</p></div>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_device_control_block_structure">Device Control Block Structure</h2>
<div class="sectionbody">
<div class="paragraph"><p>The 4.x DCB Data Structure consists of the following parts:</p></div>
<div class="ulist"><ul>
<li>
<p>
Header - The version number (e.g., 0x40 for Version 4.0), the header size, the size of each DCB Entry (currently 8 bytes), the number of valid DCB Entries, pointers to different tables, and the DCB signature. If any of the pointers here are NULL, then those tables are considered to be absent or invalid.
</p>
</li>
<li>
<p>
Device entries list - One for each display connector (two for DVI-I
connectors). Each device entry is subdivided into two main parts:
<a href="#_display_path_information">Display Path Information</a> and
<a href="#_device_specific_information">Device Specific Information</a>.
</p>
</li>
</ul></div>
</div>
</div>
<div class="sect1">
<h2 id="_device_control_block_header">Device Control Block Header</h2>
<div class="sectionbody">
<div class="tableblock">
<table rules="all"
width="100%"
frame="border"
cellspacing="0" cellpadding="4">
<caption class="title">Table 1. Device Control Block Header</caption>
<col width="27%" />
<col width="2%" />
<col width="2%" />
<col width="66%" />
<thead>
<tr>
<th align="left" valign="top"> Name </th>
<th align="right" valign="top"> Bit width </th>
<th align="center" valign="top"> Optional/Mandatory </th>
<th align="left" valign="top"> Values and Meaning</th>
</tr>
</thead>
<tbody>
<tr>
<td align="left" valign="top"><p class="table">Version</p></td>
<td align="right" valign="top"><p class="table">8</p></td>
<td align="center" valign="top"><p class="table">O</p></td>
<td align="left" valign="top"><p class="table">Version # of the DCB Header and Entries. E.g., DCB 4.0 will start with a
value of 0x40 here. A version number of zero directs the driver to use
an internal DCB table.</p></td>
</tr>
<tr>
<td align="left" valign="top"><p class="table">Header Size</p></td>
<td align="right" valign="top"><p class="table">8</p></td>
<td align="center" valign="top"><p class="table">M</p></td>
<td align="left" valign="top"><p class="table">Size of the DCB Header in Bytes. For v4.0 this will be 27 bytes.</p></td>
</tr>
<tr>
<td align="left" valign="top"><p class="table">Entry Count</p></td>
<td align="right" valign="top"><p class="table">8</p></td>
<td align="center" valign="top"><p class="table">M</p></td>
<td align="left" valign="top"><p class="table">Number of <a href="#_dcb_device_entries">DCB Device Entries</a> immediately
following this table.</p></td>
</tr>
<tr>
<td align="left" valign="top"><p class="table">Entry Size</p></td>
<td align="right" valign="top"><p class="table">8</p></td>
<td align="center" valign="top"><p class="table">M</p></td>
<td align="left" valign="top"><p class="table">Size of Each Entry in bytes. With the start of DCB 4.0, this field should be 8.</p></td>
</tr>
<tr>
<td align="left" valign="top"><p class="table">Communications Control Block Pointer</p></td>
<td align="right" valign="top"><p class="table">16</p></td>
<td align="center" valign="top"><p class="table">M</p></td>
<td align="left" valign="top"><p class="table">Pointer to the <a href="#_communications_control_block">Communications Control Block</a>. In v3.0 this was the I2C Control Block Pointer.</p></td>
</tr>
<tr>
<td align="left" valign="top"><p class="table">DCB Signature</p></td>
<td align="right" valign="top"><p class="table">32</p></td>
<td align="center" valign="top"><p class="table">M</p></td>
<td align="left" valign="top"><p class="table">DCB signature = 0x4EDCBDCB.
This is used to tell a valid DCB from an invalid one.</p></td>
</tr>
<tr>
<td align="left" valign="top"><p class="table">GPIO Assignment Table Pointer</p></td>
<td align="right" valign="top"><p class="table">16</p></td>
<td align="center" valign="top"><p class="table">M</p></td>
<td align="left" valign="top"><p class="table">Pointer to the <a href="#_gpio_assignment_table">GPIO Assignment Table</a>.</p></td>
</tr>
<tr>
<td align="left" valign="top"><p class="table">Input Devices Table Pointer</p></td>
<td align="right" valign="top"><p class="table">16</p></td>
<td align="center" valign="top"><p class="table">O</p></td>
<td align="left" valign="top"><p class="table">Pointer to the <a href="#_input_devices_table">Input Devices Table</a>.</p></td>
</tr>
<tr>
<td align="left" valign="top"><p class="table">Personal Cinema Table Pointer</p></td>
<td align="right" valign="top"><p class="table">16</p></td>
<td align="center" valign="top"><p class="table">O</p></td>
<td align="left" valign="top"><p class="table">Pointer to the <a href="#_personal_cinema_table">Personal Cinema Table</a>.</p></td>
</tr>
<tr>
<td align="left" valign="top"><p class="table">Spread Spectrum Table Pointer</p></td>
<td align="right" valign="top"><p class="table">16</p></td>
<td align="center" valign="top"><p class="table">O</p></td>
<td align="left" valign="top"><p class="table">Pointer to the <a href="#_spread_spectrum_table">Spread Spectrum Table</a>.</p></td>
</tr>
<tr>
<td align="left" valign="top"><p class="table">I2C Devices Table Pointer</p></td>
<td align="right" valign="top"><p class="table">16</p></td>
<td align="center" valign="top"><p class="table">O</p></td>
<td align="left" valign="top"><p class="table">Pointer to the <a href="#_i2c_device_table">I2C Devices Table</a>.</p></td>
</tr>
<tr>
<td align="left" valign="top"><p class="table">Connector Table Pointer</p></td>
<td align="right" valign="top"><p class="table">16</p></td>
<td align="center" valign="top"><p class="table">M</p></td>
<td align="left" valign="top"><p class="table">Pointer to the <a href="#_connector_table">Connector Table</a>.</p></td>
</tr>
<tr>
<td align="left" valign="top"><p class="table">Flags</p></td>
<td align="right" valign="top"><p class="table">8</p></td>
<td align="center" valign="top"><p class="table">M</p></td>
<td align="left" valign="top"><p class="table">See <a href="#_dcb_flags">DCB Flags</a> below</p></td>
</tr>
<tr>
<td align="left" valign="top"><p class="table">HDTV Translation Table Pointer</p></td>
<td align="right" valign="top"><p class="table">16</p></td>
<td align="center" valign="top"><p class="table">O</p></td>
<td align="left" valign="top"><p class="table">Pointer to the <a href="#_hdtv_translation_table">HDTV Translation Table</a>.
This structure is optional. If the structure is not needed, then this pointer can be set to 0.</p></td>
</tr>
<tr>
<td align="left" valign="top"><p class="table">Switched Outputs Table Pointer</p></td>
<td align="right" valign="top"><p class="table">16</p></td>
<td align="center" valign="top"><p class="table">O</p></td>
<td align="left" valign="top"><p class="table">Pointer to the <a href="#_switched_outputs_table">Switched Outputs Table</a>. This structure is optional.</p></td>
</tr>
</tbody>
</table>
</div>
<div class="paragraph"><p>An "optional" table pointer or field may be set to zero to indicate that
no table is present. If the structure is not needed, then this pointer
can be set to 0.</p></div>
<div class="admonitionblock">
<table><tr>
<td class="icon">
<div class="title">Note</div>
</td>
<td class="content">Throughout this document, a "pointer" means a byte offset relative
to the start of the VBIOS image.</td>
</tr></table>
</div>
<div class="sect2">
<h3 id="_dcb_flags">DCB Flags</h3>
<div class="paragraph"><p>Each bit flag has a different meaning.
All undefined bits are reserved and must be set to 0.</p></div>
<div class="ulist"><div class="title">DCB Flag Bits</div><ul>
<li>
<p>
Bit 0 - Boot Display Count:
</p>
<div class="ulist"><ul>
<li>
<p>
0 - Only 1 boot display is allowed.
</p>
</li>
<li>
<p>
1 - 2 boot displays are allowed.
</p>
</li>
</ul></div>
</li>
</ul></div>
<div class="paragraph"><p>These next 2 bits are all used for VIP connections.</p></div>
<div class="ulist"><ul>
<li>
<p>
Bits 5:4 - VIP location. Possible values are:
</p>
<div class="ulist"><ul>
<li>
<p>
00b - No VIP.
</p>
</li>
<li>
<p>
01b - VIP is on Pin Set A.
</p>
</li>
<li>
<p>
10b - VIP is on Pin Set B.
</p>
</li>
<li>
<p>
11b - Reserved
</p>
</li>
</ul></div>
</li>
</ul></div>
<div class="paragraph"><p>These next 2 bits are used for Distributed Rendering (DR) configuration.</p></div>
<div class="ulist"><ul>
<li>
<p>
Bit 6 - All capable DR ports: Pin Set A:
</p>
<div class="ulist"><ul>
<li>
<p>
1 - Pin Set A is routed to a SLI Finger.