C89C90

C89C90 is a designation that has appeared in relation to 8-bit microcontrollers, but there is no single, widely standardized device by that exact name. In practice, C89C90 often refers to a family or line of 8051-compatible microcontrollers sold by various vendors, with each vendor offering different on‑chip resources and peripherals. Because the designation is used by multiple manufacturers, the specific memory sizes, I/O counts, and peripheral sets can vary significantly between revisions.

Typical features associated with 8051-based microcontrollers that might be described by a C89C90 label include an ALU operating on an 8-bit data path, on‑chip program memory (ROM or flash), RAM, multiple I/O ports, and a range of integrated peripherals such as timers, a serial communication unit (UART), and an interrupt controller. Clock frequencies for these devices generally span from a few megahertz to tens of megahertz, with memory capacities and peripheral options managed by the particular model and vendor. Packaging is commonly available in DIP, SOIC, and QFP formats to suit hobbyist boards and commercial products.

Development for C89C90 devices typically uses standard 8051 toolchains, including C or assembly language compilers, and vendor-specific programming interfaces. They are employed in embedded control applications, consumer electronics, and education due to their low cost and straightforward integration with existing 8051 ecosystems. Given the variance among vendors, users seeking precise specifications should consult the specific datasheet and development resources for the exact C89C90 part number in question. Related topics include the 8051 architecture and other vendor-specific 89C-series microcontrollers.