Eight- to Sixteen-Bit Universal Synchronous/Asynchronous Receiver and Transmitter Conversion
Original Publication Date: 1989-Feb-01
Included in the Prior Art Database: 2005-Jan-27
This article describes a circuit arrangement which converts a single, standard, 8-bit-wide universal synchronous/asynchronous receiver and transmitter (USART) in such a way as to appear to be a 16-bit-wide USART to a 16-bit microprocessor. Large-scale integrated circuits, such as gate arrays, contain an abundance of logic gates. The circuitry required to implement this mechanism can be fitted into left-over logic. This provides the capability of implementing this mechanism without consuming real estate on a card. The drawing shows the basic design of the 8- to 16-bit USART converter. During a write cycle, the 16-bit microprocessor places a 16-bit word on the data bus. The control logic enables the high byte tri-state drivers and provides the control signals to write it into memory.