MC68030RC33

Manufacturer Part NumberMC68030RC33
DescriptionMC68030RC33ENHANCED 32-BIT MICROPROCESSOR
ManufacturerMotorola
MC68030RC33 datasheet
 


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
Page 301
302
Page 302
303
Page 303
304
Page 304
305
Page 305
306
Page 306
307
Page 307
308
Page 308
309
Page 309
310
Page 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
Page 307/602

Download datasheet (4Mb)Embed
PrevNext
L/U
This bit specifies the type of limit in the LIMIT field. When the L/U bit is set, the LIMIT field
contains the unsigned lower limit; the index value for the next level of the tree must be
greater than or equal to the value in the LIMIT field. When the bit is cleared, the limit is an
unsigned upper limit, and the index value must be less than or equal to the LIMIT. An out-
of-bounds access causes the B bit in the ATC entry for the address to be set and causes
the table search to abort.
LIMIT
This 15-bit field contains a limit to which the index portion of an address is compared to
detect an out-of-bounds index. The limit check applies to the index into the table at the
next lower level of the translation tree. If the descriptor is an early termination page de-
scriptor, the limit field is still used as a check on the next index field of the logical address.
M
This bit identifies a modified page. The MC68030 sets the M bit in the corresponding page
descriptor before a write operation to a page for which the M bit is zero, except after a
descriptor with the WP bit set is encountered, or after a supervisor violation is encoun-
tered. An access is considered to be a write for updating purposes if either the R/W or
RMC signal is low. The MC68030 never clears this bit.
PAGE ADDRESS
This 24-bit field contains the physical base address of a page in memory. The low-order
bits of the address are supplied by the logical address. When the page size is larger than
256 bytes, one or more of the least significant bits of this field are not used. The number
of unused bits is equal to the PS field value in the TC register minus eight.
S
This bit identifies a pointer table or a page as a supervisor only table or page. When the
S bit is set, only programs operating at the supervisor privilege level are allowed to access
the portion of the logical address mapped by this descriptor. If this bit is clear, accesses
using this descriptor are not restricted to supervisor-only unless the access is restricted
by some other level of the translation tree.
TABLE ADDRESS
This 28-bit field contains the physical base address of a table of descriptors. The low-or-
der bits of the address are supplied by the logical address.
MOTOROLA
MC68030 USER’S MANUAL
Memory Management Unit
9-19