## Input/Output Device Driver Reference

[prev][next][parent][TOC]

### States of the ASYNC Device Driver

The different processing states of the physical ASYNC device driver, the ASYNC hardware, and the ASYNC control signals are listed below:

Automatic Receive Flow Control (XON/XOFF)
Automatic Transmit Flow Control (XON/XOFF)
Bit Rate
Break Replacement Character
Break Replacement Character Processing
COM Event WORD and COM Error WORD
Data Bits
DTR and RTS
DTR Control Mode
Error Replacement Character
Error Replacement Character Processing
Extended Hardware Buffering
Input Sensitivity Using DSR
Null Stripping
Output Handshaking Using CTS, DSR, DCD
Parity
RTS Control Mode
Read Timeout State
Read Timeout Value
Stop Bits
Transmit Immediate
Transmitting Break
Write Timeout State
Write Timeout Value
XON/XOFF Characters

Each of the above states are covered as follows:

A brief description.
The initial (default) value.
The effect on the physical device driver when the physical device driver receives an OPEN request packet for the port and the port is not already open (from a previous OPEN without a matching CLOSE). This is called a First Level Open. If applicable, the way the state of the physical device driver is affected by a CLOSE request packet.
How the MODE utility can be used to alter the state of this item or how the MODE utility will alter the state of this item.
The effect on the physical device driver of the state of Extended Hardware Buffering. In particular, special considerations relating to Automatic Protocol Override are given where the protocol being described is affected by this feature of the physical ASYNC device driver.