The STC90C52RC-40I is a single-chip 8-bit Flash-type microcontroller with a 40MHz STC LQFP-44_10x10x08P RoHS package manufactured by STC. The microcontroller includes a range of interfaces such as two 8-bit bi-directional ports (P0-P3 and P4-P7), three 8-bit bi-directional ports (P1-P3 on the same side as P0-P3, and P3-P7 on the opposite side of the chip) for control applications, a programmable 16-bit timer, a programmable watch dog timer, an 8-bit A/D converter with 10 channels, two power-saving modes, and several operating modes. It also has an 8K x 8-bit Flash memory for user program and data storage, a 32KB x 8-bit external RAM for program and data memory, and a built-in ROM for program initialization and other user-defined tasks. It is compatible with direct debugging and in-circuit emulation for the STC90C52RC-40I microcontroller. The microcontroller can be programmed in assembly or high-level language such as C.