The KS57C0502/C0504 single-chip CMOS microcontroller has been designed for high-performance using Samsung's newest 4-bit CPU core, SAM47 (Samsung Arrangeable Microcontrollers). The KS57P0504 is the microcontroller which has 4 Kbyte one-time-programmable ROM and the functions are the same to KS57C0502/C0504. With a four-channel comparator, eight LED direct drive pins, serial I/O interface, and its versatile 8-bit timer/counter, the KS57C0502/C0504 offers an excellent design solution for a wide variety of general-purpose applications. Up to 24 pins of the 30-pin SDIP package can be dedicated to I/O. Five vectored interrupts provide fast response to internal and external events. In addition, the KS57C0502/C0504's advanced CMOS technology provides for very low power consumption and a wide operating voltage range -- all at a very low cost.