Zilog, often seen as ZiLOG, is a manufacturer of 8-bit, 16-bit, 24-bit, and 32-bit CPUs, and is most famous for its Intel 8080-compatible Z80 series. Zilog was incorporated in California in 1974 by Federico Faggin, who left Intel after working on the 8080, and the Z80 was a vast improvement over it (it was faster, etc.).
The Z80 was a best seller because it was much cheaper than the 8080. It was used in the Nintendo Game Boy, the Sinclair ZX-80, ZX-81 and ZX Spectrum home microcomputer as well as the MSX and the TRS-80 - among many others. Also, many Texas Instruments graphing calculators used the Z80 as the main processor and in some newer game consoles as a secondary processor, like the Mega Drive. The CP/M operating system (and its huge software library featuring hits like Wordstar and dBase) was known to be "the Z80 disk operating system", and its success is partly due to the popularity of the Z80.

After the Z80 Zilog introduced 16-bit and 32-bit processors, but these were not particularly successful, and the company refocused on the microcontroller market, producing both basic CPUs and application-specific integrated circuits/standard products (ASICs/ASSPs) built around a CPU core. As well as producing processors, Zilog has produced several other components. One of the most famous was the Z8530 serial communications controller as found on Sun SPARCstations and SPARCservers up to the SPARCstation 20.

The company became a subsidiary of Exxon in 1980, but the management and employees bought it back in 1989. It went public in 1991, but was acquired in 1998 by Texas Pacific Group, who, after chip prices plummeted, reorganized the company in a Chapter 11 bankruptcy in late 2001.