Rev. 1.0, 02/00, page ix of 19
16.1.1
Features............................................................................................................. 313
16.1.2
Block Diagram.................................................................................................. 314
16.1.3
Pin Configuration ............................................................................................. 315
16.1.4
Register Configuration...................................................................................... 316
16.2
Register Descriptions ........................................................................................................ 317
16.2.1
Free Running Counter (FRC) ........................................................................... 317
16.2.2
Output Comparing Registers A and B (OCRA and OCRB) ............................. 318
16.2.3
Input Capture Registers A Through D (ICRA Through ICRD)........................ 319
16.2.4
Timer Interrupt Enabling Register (TIER) ....................................................... 321
16.2.5
Timer Control/Status Register X (TCSRX) ...................................................... 324
16.2.6
Timer Control Register X (TCRX) ................................................................... 328
16.2.7
Timer Output Comparing Control Register (TOCR) ........................................ 330
16.2.8
Module Stop Control Register (MSTPCR)....................................................... 332
16.3
Operation .......................................................................................................................... 333
16.3.1
Operation of Timer X1 ..................................................................................... 333
16.3.2
Counting Timing of the FRC ............................................................................ 334
16.3.3
Output Comparing Signal Outputting Timing .................................................. 335
16.3.4
FRC Clearing Timing ....................................................................................... 335
16.3.5
Input Capture Signal Inputting Timing............................................................. 336
16.3.6
Input Capture Flag (ICFA through ICFD) Setting Up Timing ......................... 337
16.3.7
Output Comparing Flag (OCFA and OCFB) Setting Up Timing ..................... 338
16.3.8
Overflow Flag (CVF) Setting Up Timing......................................................... 338
16.4
Operation Mode of Timer X1 ........................................................................................... 339
16.5
Interrupt Causes ................................................................................................................ 340
16.6
Exemplary Uses of Timer X1 ........................................................................................... 341
16.7
Precautions when Using Timer X1 ................................................................................... 342
16.7.1
Competition between Writing and Clearing with the FRC ............................... 342
16.7.2
Competition between Writing and Counting Up with the FRC ........................ 343
16.7.3
Competition between Writing and Comparing Match with the OCR ............... 344
16.7.4
Changing Over the Internal Clocks and Counter Operations............................ 345
Section 17 Watchdog Timer (WDT)
.............................................................................. 347
17.1
Overview........................................................................................................................... 347
17.1.1
Features............................................................................................................. 347
17.1.2
Block Diagram.................................................................................................. 348
17.1.3
Register Configuration...................................................................................... 349
17.2
Register Descriptions ........................................................................................................ 350
17.2.1
Watchdog Timer Counter (WTCNT)................................................................ 350
17.2.2
Watchdog Timer Control/Status Register (WTCSR)........................................ 350
17.2.3
System Control Register (SYSCR)................................................................... 353
17.2.4
Notes on Register Access ................................................................................. 354
17.3
Operation .......................................................................................................................... 355
17.3.1
Watchdog Timer Operation .............................................................................. 355