HD6417751 Datasheet, PDF (12/1105 Pages) Renesas Technology Corp – SuperH RISC engine

10.8.3 Notes on Register Access................................................................................. 257
10.9 Using the WDT............................................................................................................ 258
10.9.1 Standby Clearing Procedure............................................................................. 258
10.9.2 Frequency Changing Procedure ....................................................................... 258
10.9.3 Using Watchdog Timer Mode.......................................................................... 259
10.9.4 Using Interval Timer Mode.............................................................................. 259
10.10 Notes on Board Design ................................................................................................ 260
Section 11 Realtime Clock (RTC) .............................................................................. 263
11.1 Overview..................................................................................................................... 263
11.1.1 Features........................................................................................................... 263
11.1.2 Block Diagram ................................................................................................ 264
11.1.3 Pin Configuration ............................................................................................ 265
11.1.4 Register Configuration..................................................................................... 265
11.2 Register Descriptions ................................................................................................... 267
11.2.1 64 Hz Counter (R64CNT)................................................................................ 267
11.2.2 Second Counter (RSECCNT)........................................................................... 267
11.2.3 Minute Counter (RMINCNT) .......................................................................... 268
11.2.4 Hour Counter (RHRCNT)................................................................................ 268
11.2.5 Day-of-Week Counter (RWKCNT).................................................................. 269
11.2.6 Day Counter (RDAYCNT) .............................................................................. 270
11.2.7 Month Counter (RMONCNT).......................................................................... 270
11.2.8 Year Counter (RYRCNT) ................................................................................ 271
11.2.9 Second Alarm Register (RSECAR).................................................................. 272
11.2.10 Minute Alarm Register (RMINAR).................................................................. 272
11.2.11 Hour Alarm Register (RHRAR)....................................................................... 273
11.2.12 Day-of-Week Alarm Register (RWKAR)......................................................... 273
11.2.13 Day Alarm Register (RDAYAR) ..................................................................... 274
11.2.14 Month Alarm Register (RMONAR) ................................................................. 275
11.2.15 RTC Control Register 1 (RCR1) ...................................................................... 275
11.2.16 RTC Control Register 2 (RCR2) ...................................................................... 277
11.2.17 RTC Control Register (RCR3) and Year-Alarm Register (RYRAR)
(SH7751R Only) ............................................................................................. 280
11.3 Operation..................................................................................................................... 281
11.3.1 Time Setting Procedures.................................................................................. 281
11.3.2 Time Reading Procedures ................................................................................ 282
11.3.3 Alarm Function ............................................................................................... 284
11.4 Interrupts ..................................................................................................................... 285
11.5 Usage Notes................................................................................................................. 285
11.5.1 Register Initialization ...................................................................................... 285
11.5.2 Carry Flag and Interrupt Flag in Standby Mode................................................ 285
11.5.3 Crystal Oscillator Circuit ................................................................................. 285
Rev. 3.0, 04/02, page x of xxxviii