In other words, 555 Timer is a circuit which may be connectedFrom:http://www.electricaltechnology.org/2014/12/555-timer.html 8-bit Microcontroller with 4K Bytes In-System Programmable ...Features ??? Compatible with MCS??-51 Products ??? 4K Bytes of In-System Programmable (ISP) Flash Memory ??? Endurance: 10,000 Write/Erase Cycles ??? 4.0V to 5.5V ...From:http://www.atmel.com/Imag