The PIC16F628A-I/SO is a 8-bit flash-based CMOS Microcontrollers with nanoWatt technology. All PIC® microcontrollers employ an advanced RISC architecture. The PIC16F628A have enhanced core features, an eight-level deep stack and multiple internal and external interrupt sources. The separate instruction and data buses of the Harvard architecture allow a 14-bit wide instruction word with the separate 8-bit wide data. The two-stage instruction pipeline allows all instructions to execute in a single cycle, except for program branches (which require two cycles). A total of 35 instructions (reduced instruction set) are available, complemented by a large register set. This device has integrated features to reduce external components, thus reducing system cost, enhancing system reliability and reducing power consumption.