10.9 Using the WDT ................................................................................................................. 263
10.9.1 Standby Clearing Procedure................................................................................. 263
10.9.2 Frequency Changing Procedure ........................................................................... 264
10.9.3 Using Watchdog Timer Mode.............................................................................. 264
10.9.4 Using Interval Timer Mode.................................................................................. 265
10.10 Notes on Board Design...................................................................................................... 265
Section 11 Realtime Clock (RTC) .................................................................................. 267
11.1 Overview........................................................................................................................... 267
11.1.1 Features ................................................................................................................ 267
11.1.2 Block Diagram ..................................................................................................... 268
11.1.3 Pin Configuration................................................................................................. 269
11.1.4 Register Configuration ......................................................................................... 269
11.2 Register Descriptions ........................................................................................................ 271
11.2.1 64 Hz Counter (R64CNT).................................................................................... 271
11.2.2 Second Counter (RSECCNT)............................................................................... 271
11.2.3 Minute Counter (RMINCNT) .............................................................................. 272
11.2.4 Hour Counter (RHRCNT).................................................................................... 272
11.2.5 Day-of-Week Counter (RWKCNT) ..................................................................... 273
11.2.6 Day Counter (RDAYCNT) .................................................................................. 274
11.2.7 Month Counter (RMONCNT).............................................................................. 274
11.2.8 Year Counter (RYRCNT) .................................................................................... 275
11.2.9 Second Alarm Register (RSECAR)...................................................................... 276
11.2.10 Minute Alarm Register (RMINAR) ..................................................................... 276
11.2.11 Hour Alarm Register (RHRAR)........................................................................... 277
11.2.12 Day-of-Week Alarm Register (RWKAR)............................................................ 277
11.2.13 Day Alarm Register (RDAYAR) ......................................................................... 278
11.2.14 Month Alarm Register (RMONAR)..................................................................... 279
11.2.15 RTC Control Register 1 (RCR1).......................................................................... 279
11.2.16 RTC Control Register 2 (RCR2).......................................................................... 281
11.2.17 RTC Control Register 3 (RCR3) and Year-Alarm Register (RYRAR)
(SH7750R Only) .................................................................................................. 283
11.3 Operation........................................................................................................................... 285
11.3.1 Time Setting Procedures ...................................................................................... 285
11.3.2 Time Reading Procedures .................................................................................... 286
11.3.3 Alarm Function .................................................................................................... 288
11.4 Interrupts ........................................................................................................................... 289
11.5 Usage Notes....................................................................................................................... 289
11.5.1 Register Initialization ........................................................................................... 289
11.5.2 Carry Flag and Interrupt Flag in Standby Mode................................................... 289
11.5.3 Crystal Oscillator Circuit...................................................................................... 289
Rev. 6.0, 07/02, page xxvi of I
RENESAS [ RENESAS TECHNOLOGY CORP ]
