Internal high precision R/C clock (+0.3%),+ 1% temperature drift (-40°C ~ +85°C), temperature drift +0.6% (-20°C ~ +65°C) at normal temperature The resources supporting power-down wake-up are: INT0/INT1 (rising edge/falling edge interrupt), INT2/INT3/INT4 (falling edge interrupt): CCP0/CCP1/RxD/RxD2RxD3/RxD4/T0/T1/T2/T3/T4 pin: special timer for internal power-down wake-up High-speed ADC,8-channel 10-bit, speed up to 300000 times/sec, 8-channel PWM can also be used as 8-channel D/A Comparator, which can be used as a 1-way ADC and can be used for power failure detection, supports comparison between external pin CMP + and external pin CMP-, can generate interruption, and can generate output on pin CMPO (polarity can be set), and also supports comparison between external pin CMP + and internal reference voltage 6-channel 15-bit specialized high-precision PWM (with dead zone control) +2-channel CCP (2-channel 11-16-bit PWM can be realized by using its high-speed pulse output function)-it can be used to realize another 8-channel D/A, or 2 16-bit timers, or 2 external interrupts (supporting rising/falling edge interrupts) A total of 7 timers/counters, 5 16-bit reloadable timers/counters (T0/T1/T2/T3/T4, where TO and T1 are compatible with common 8051 timers/counters), and can realize clock output. In addition, pin SysCIkO can divide the system clock into external frequency output (÷ 1 or ÷ 2 or ÷ 4 or ÷ 16), and 2 CCP can realize another 2 timers Programmable clock output function (clock frequency division output for internal system clock or clock input of external pins):? T0 outputs clock at P3.5; ? T1 outputs clock at P3.4; ? T2 outputs clock at P3.0: ? T3 outputs clock at P0.4: ? T4 outputs clock at P0.6, and the above five timer/counter output clocks can all be output at 1-65536 stages; ? The system clock outputs the clock externally at P5.4/SysClkO (the main clock of STC15 series 8-pin microcontroller outputs the clock externally at P3.4MCLKO)