NEC 78K0 User Manual page 14

CHAPTER 6 CLOCK GENERATOR .................................................................................................... 141
6.1 Functions of Clock Generator ............................................................................................... 141
6.2 Configuration of Clock Generator......................................................................................... 141
6.3 Registers Controlling Clock Generator ................................................................................ 143
6.4 System Clock Oscillator......................................................................................................... 150
6.4.1 X1 oscillator................................................................................................................................ 150
6.4.2 Subsystem clock oscillator ......................................................................................................... 150
6.4.3 When subsystem clock is not used ............................................................................................ 153
6.4.4 Ring-OSC oscillator.................................................................................................................... 153
6.4.5 Prescaler .................................................................................................................................... 153
6.5 Clock Generator Operation .................................................................................................... 154
6.6 Time Required to Switch Between Ring-OSC Clock and X1 Input Clock ......................... 161
6.7 Time Required for CPU Clock Switchover ........................................................................... 162
6.8 Clock Switching Flowchart and Register Setting ................................................................ 163
6.8.1 Switching from Ring-OSC clock to X1 input clock ...................................................................... 163
6.8.2 Switching from X1 input clock to Ring-OSC clock ...................................................................... 164
6.8.3 Switching from X1 input clock to subsystem clock ..................................................................... 165
6.8.4 Switching from subsystem clock to X1 input clock ..................................................................... 166
6.8.5 Register settings......................................................................................................................... 167
CHAPTER 7 16-BIT TIMER/EVENT COUNTERS 00 AND 01......................................................... 168
7.1 Functions of 16-Bit Timer/Event Counters 00 and 01 ......................................................... 168
7.2 Configuration of 16-Bit Timer/Event Counters 00 and 01................................................... 169
7.3 Registers Controlling 16-Bit Timer/Event Counters 00 and 01 .......................................... 174
7.4 Operation of 16-Bit Timer/Event Counters 00 and 01 ......................................................... 185
7.4.1 Interval timer operation............................................................................................................... 185
7.4.2 PPG output operations ............................................................................................................... 188
7.4.3 Pulse width measurement operations ........................................................................................ 191
7.4.4 External event counter operation................................................................................................ 199
7.4.5 Square-wave output operation ................................................................................................... 202
7.4.6 One-shot pulse output operation ................................................................................................ 204
7.5 Cautions for 16-Bit Timer/Event Counters 00 and 01.......................................................... 209
CHAPTER 8 8-BIT TIMER/EVENT COUNTERS 50 AND 51........................................................... 212
8.1 Functions of 8-Bit Timer/Event Counters 50 and 51 ........................................................... 212
8.2 Configuration of 8-Bit Timer/Event Counters 50 and 51..................................................... 214
8.3 Registers Controlling 8-Bit Timer/Event Counters 50 and 51 ............................................ 216
8.4 Operations of 8-Bit Timer/Event Counters 50 and 51 ......................................................... 221
8.4.1 Operation as interval timer ......................................................................................................... 221
8.4.2 Operation as external event counter .......................................................................................... 223
8.4.3 Square-wave output operation ................................................................................................... 224
8.4.4 PWM output operation................................................................................................................ 225
8.5 Cautions for 8-Bit Timer/Event Counters 50 and 51............................................................ 229
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User's Manual U15947EJ2V0UD