Specifications

Serial Communications (16C452)
OVERVIEW
This chapter describes the two 16C450-equivalent serial ports
available on the ZT 8809A. They are referred to as COM1 and COM2
in STD DOS systems and ports 1 and 2 in non-DOS systems. These
two serial ports are contained within the VL 16C452 Communications
Element from VLSI Technologies.
The first section of this chapter details an overview of the software
communications priority scheme, with a basic outline of the protocol
between two serial devices. The second section details the serial port
signals, and the third section contains the register addresses and
definitions.
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