M30843FJFP

Manufacturer Part NumberM30843FJFP
ManufacturerRenesas Electronics Corporation.
M30843FJFP datasheets

Availability: In stock

International delivery:

Added to cart

Select quantity

 
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
Page 151
152
Page 152
153
Page 153
154
Page 154
155
Page 155
156
Page 156
157
Page 157
158
Page 158
159
Page 159
160
Page 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
Page 152/529:

Watchdog Timer

Download datasheet (4Mb)Embed
PrevNext
M
3
2
C
8 /
4
G
o r
u
p
(
M
3
2
C
8 /
, 4
M
3
2
12. Watchdog Timer
The watchdog timer monitors the program executions and detects defective program. It allows the micro-
computer to trigger a reset or to generate an interrupt if the program error occurs. The watchdog timer
contains a 15-bit counter, which is decremented by the CPU clock that the prescaler divides. The CM06 bit
in the CM0 register determines whether a watchdog timer interrupt request or reset is generated if the
watchdog timer underflows. The CM06 bit can only be set to "1" (reset). Once the CM06 bit is set to "1", it
cannot be changed to "0" ( watchdog timer interrupt) by program. The CM06 bit is set to "0" only after reset.
When the main clock, on-chip oscillator clock, or PLL clock runs as the CPU clock, the WDC7 bit in the
WDC register determine whether the prescaler divides the clock by 16 or by 128. When the sub clock runs
as the CPU clock, the prescaler divides the clock by 2 regardless of the WDC7 bit setting. Watchdog timer
cycle is calculated as follows. Marginal errors, due to the prescaler, may occur in watchdog timer cycle.
When the main clock, on-chip oscillator clock, or PLL clock is selected as the CPU clock,
Watchdog timer cycle =
When the sub clock is selected as the CPU clock,
Watchdog timer cycle =
For example, if the CPU clock frequency is 30MHz and the prescaler divides it by 16, the watchdog timer
cycle is approximately 17.5 ms.
The watchdog timer is reset when the WDTS register is set and when a watchdog timer interrupt request is
generated. The prescaler is reset only when the microcomputer is reset. Both watchdog timer and prescaler
stop after reset. They begin counting when the WDTS register is set.
The watchdog timer and prescaler stop in stop mode, wait mode and hold state. They resume counting
from the value held when the mode or state is exited.
Figure 12.1 shows a block diagram of the watchdog timer. Figure 12.2 shows registers associated with the
watchdog timer.
CPU Clock
HOLD Signal
Write to WDTS Register
Internal Reset Signal
CM06, CM07 : Bits in the CM0 Register
WDC7 : Bit in the WDC Register
PM22 : Bit in the PM2 Register
Figure 12.1 Watchdog Timer Block Diagram
Page 131
R
e
. v
1
0 .
1
J
u
. l
0
, 7
2
0
0
5
R
E
J
0
9
B
0
0
3
6
0 -
1
0
1
C
8 /
4
) T
Divide-by-16 or -128 prescaler x counter value of watchdog timer (32768)
CPU clock
Divide-by-2 prescaler x counter value of watchdog timer (32768)
CPU clock
Prescaler
CM07 = 0
WDC7 = 0
1/16
PM22 = 0
CM07 = 0
WDC7 = 1
1/128
CM07 = 1
1/2
On-chip Oscillator Clock
PM22 = 1
f o
4
9
5
12. Watchdog Timer
CM06 = 0

Watchdog Timer

Interrupt Request

Watchdog Timer

Reset
CM06 = 1
Set to
7FFF
16

Related parts for M30843FJFP

Part Number DescriptionManufacturer Datasheet
  m30843mw-xxxgp Renesas 16/32-bit Single-chip Microcomputer M16c Family / M32c/80 Series Renesas Electronics Corporation.
  M30835FJGP D3 Renesas Electronics Corporation.
M3087BFLGP#U3  M3087BFLGP#U3 IC M32C/87 MCU FLASH 144LQFP Renesas Electronics America
M30843FWGP#U5  M30843FWGP#U5 IC M32C MCU FLASH 320K 100LQFP Renesas Electronics America
M30843FJGP#U5  M30843FJGP#U5 IC M32C MCU FLASH 512K 100LQFP Renesas Electronics America
M30843FJGP#U3  M30843FJGP#U3 IC M32C MCU FLASH 512K 100LQFP Renesas Electronics America
M30853FJGP#U3  M30853FJGP#U3 IC M32C MCU FLASH 100LQFP Renesas Electronics America
M3087BFLBGP#U3  M3087BFLBGP#U3 IC M32C/87 MCU FLASH 144LQFP Renesas Electronics America
M30833FJGP#U3  M30833FJGP#U3 IC M32C/83 MCU FLASH 100LQFP Renesas Electronics America
M30873FHAGP#U5  M30873FHAGP#U5 IC M32C/87 MCU FLASH 100LQFP Renesas Electronics America
M30873FHBGP#U3  M30873FHBGP#U3 IC M32C/87 MCU FLASH 100LQFP Renesas Electronics America
M30873FHAGP#U3  M30873FHAGP#U3 IC M32C/87 MCU FLASH 100LQFP Renesas Electronics America
M30879FKBGP#U5  M30879FKBGP#U5 IC M32C/87 MCU FLASH 100LQFP Renesas Electronics America
M30843FHFP#U5  M30843FHFP#U5 IC M32C MCU FLASH 384K 100QFP Renesas Electronics America
M30853FHFP#U5  M30853FHFP#U5 IC M32C MCU FLASH 384K 100QFP Renesas Electronics America