The STC15W201S-35I-SOP16 is an integrated circuit (IC) manufactured by STC, with an SOP-16 (150mil) RoHS package type. It is an 8051 based, single-clock-cycle instruction-executing enhanced 8051 MCU. It has features including 128K Bytes of Flash, 2K Bytes of RAM, clock speed up to 35MHz, Power-down/ Idle/ GATE/ WAIT/ SM or Stop mode, three 16-bit timers/counters and one of the two on-chip UARTs. This IC also has a built-in intelligent watch-dog timer, dual Data EEPROM and development support. It is a low-power, high-performance microcontroller that is used in several applications, such as HID, Lighting, MCU independent application and so on.