CHAPTER 6 CLOCK GENERATION FUNCTION1416.4.4 Software STOP mode(1) Settings and operating statesThis mode stops the entire system by stopping the clock oscillator (generator) and by stopping the internal mainclock. The sub clock oscillator continues operating and the on-chip sub clock supply is continued. When theFRC bit in the processor clock control register (PCC) is set (to “1”), the sub clock oscillator’s on-chip feedbackresistance is cut. This sets ultra low power consumption mode during which the only current is the device’s leakcurrent.During this mode, program execution is stopped and the contents of all registers and on-chip RAM are retainedas they were just before software STOP mode was set. When the resonator is connected, i.e., when the CESELbit in the power saving control register (PSC) has been cleared (to “0”), an oscillation stabilization time is requiredafter the mode is canceled.This mode can be set only when the main clock is being used as the CPU clock. This mode is set when the STPbit in the power saving control register (PSC) has been set (to “1”).Do not set this mode when the sub clock has been selected as the CPU clock.The operating states for software STOP mode are listed in Table 6-3.Table 6-3. Operating States during Software STOP Mode (1/2)Mode SettingsItemWhen Sub Clock Exists When Sub Clock Does Not ExistCPU StoppedClock oscillator Oscillation for main clock is stopped, oscillation for sub clock continues (in some cases)Clock supply to CPU and on-chip peripheral functions is stopped16-bit timer (TM0) Operates when INTWTI is selected for countclock (fxt is selected as count clock for watchtimer)Stopped16-bit timer (TM1) Stopped8-bit timer (TM2) Stopped8-bit timer (TM3) Stopped8-bit timer (TM4) Operates when fxt is selected for count clock Stopped8-bit timer (TM5) Operates when fxt is selected for count clock StoppedWatch timer Operates when fxt is selected for count clock StoppedWatchdog timer StoppedSIO0-SIO2 Operates when an external clock is selected as the serial clockI2CNoteStoppedUART0,UART1Operates when an external clock is selected as the serial clockA/D converter StoppedDMA0-DMA2 StoppedNoteμPD703015Y and 70F3017Y onlySerialinterface
