The 8251 is a Universal Synchronous/Asynchronous Receiver/Transmitter (USART) packaged in a 28-pin DIP made by Intel. It is typically used for serial communication and was rated for per second signalling rate.
It is commonly confused with the much more common 8250 UART that was made popular as the serial port in the IBM Personal Computer.
It includes 5 sections: read/write control logic transmitter receiver data bus system modem control
Variants
Model Number Temperature Range Date of Release Price (USD)In quantities of 100 and up ID8251 Industrial March/April 1979Intel Corporation, "Microcomputer Component: New industrial grade product line answers the demand for high-reliability components to operate in industrial applications.", Intel Preview, March/April 1979, Pg. 11 $25.10 8251A Commercial May/June 1980Intel Corporation, "Intel peripherals enhance 8086 system design", Intel Preview Special Issue: 16-Bit Solution, May/June 1980, Pg. 22 $6.40
Known uses
The Intel 8251A was used in the Intel SDK-86 MCS-86 System Design Kit and the DEC LA120 printing terminal.LA120 Technical Manual The device is also used in the IC-10 RS-232 interface kit used in Kenwood amateur radios like the TS-440S, TS-711, TS-811 and many others.
External links and references Mikrocomputer Bausteine, Datenbuch 1979/80, Band 3, Peripherie, Siemens AG, Bestellnummer B 2049, pp. 64–101. NEC Electronics (Europe) GmbH, 1982 Catalog, pp. 631–648 Intel Corporation, "8251 Programmable Communication Interface", Intel 8080 Microcomputer Systems User's Manual, September 1975, page 5-135 from bitsaver.org in PDF