.The CMS79F5139 is an SOP-16 RoHS Other Processors and Microcontrollers (MCUs) device, manufactured by Cmsemicon. It is a low-voltage CMOS device, containing an 8-bit CPU with an 8-bit ROM, 128 bytes RAM, 20 I/O lines, 2 internal ROMs, and an internal Brown Out detect circuit. The CMS79F5139 operates from 1.8V to 5V, and has increased instruction speed (up to 8 MHz). The CMS79F5139 is compatible with 8051 and 8052 microcontrollers, allowing fast prototyping and development cycles. It features a 40-pin non-parallel package, allowing for ease of use and lower costs. Additionally, the CMS79F5139 has a wide temperature range, -40°C to +85°C, allowing for reliable operation in extreme environments.