Chapter 4Clock/ Mode/ Voltage ControlIV - 2 Clock Control4.1 Clock ControlThe LSI has 4 types of clock oscillation circuits.Table:4.1.1 Clock Oscillation CircuitsFigure:4.1.1 Block Diagram of Clock Control..After reset, the LSI operates in SLOW mode where SYSCLK is equal to SRCCLK.....To lower the LSI power consumption, the clock supply to the peripheral circuits can be con-trolled with the PRICKCNT0/1/2 registers.For example, if Timer 0 is not used, the clock supply to Timer 0 is stopped by setting thePRICKCNT0.PRICKCNT00 to "0"...Internal high-speed oscillation circuit Max. 10 MHz clock (HRCCLK) can be generated.External high-speed oscillation circuit High-speed clock is generated by connecting crystal or ceramic oscillatorto OSC1/OSC2 pins.Internal low-speed oscillation circuit 40 kHz clock (SRCCLK) can be generated.External low-speed oscillation circuit Low-speed clock is generated by connecting crystal oscillator to XI/XOpins.MUXMUXHCLK(High-speed Clock)SYSCLK (*)(System Clock)HSCLK HSCLKDividerExternalHigh-speedOscillationHOSCCLKInternalHigh-speedOscillationHRCCLKOSC1OSC2ExternalLow-speedOscillationXIXOInternalLow-speedOscillationSRCCLKMUXSOSCCLK1/2Divider OSCSTBCLK(Oscillation Stabilization Clock)SCLK(Low-speed Clock)SCLKCNT.SCLKSELHCLKCNT.HCLKSELCPUM.CLKSEL* CKCTR.OSCSEL2-0 control the divider ratio of SYSCLK.SCLKCNT.SRCCNTCPUM.XIMOD Operation EnableCPUM.STOPSCLKCNT.SOSCCNTCPUM.XIMODCPUM.STOPOperation EnableHCLKCNT.HRCCNTCPUM.OSCMOD Operation EnableCPUM.STOPHCLKCNT.HOSCCNTCPUM.OSCMODCPUM.STOPOperation Enable