CDP1854A

The CDP1854A and CDP1854AC are silicon-gate CMOS Universal Asynchronous Receiver/Transmitter (UART) circuits. They are designed to provide the necessary formatting and control for interfacing between serial and parallel data. For example, these UARTs can be used to interface between a peripheral or terminal with serial I/O ports and the 8-bit CDP1800-series microprocessor parallel data bus system. The CDP1854A is capable of full duplex operation, i.e., simultaneous conversion of serial input data to parallel output data and parallel input data to serial output data.

The CDP1854A UART can be programmed to operate in one of two modes by using the mode control input. When the input is high (MODE = 1), the CDP1854A is directly compatible with the CDP1800-series microprocessor system without additional interface circuitry. When the mode input is low (MODE = 0), the device is functionally compatible with industry standard UART's such as the TR1602A and CDP6402. It is also pin compatible with these types, except that pin 2 is used for the mode control input.

The CDP1854A and the CDP1854AC are functionally identical. The CDP1854A has a recommended operating voltage range of 4V to 10.5V, and the CDP1854AC has a recommended operating voltage range of 4V to 6.5V.