using-serial-sys-and-serenum-sys.md

title	description	keywords	ms.date
Using Serial.sys and Serenum.sys	Using Serial.sys and Serenum.sys	serial ports WDK serial devices WDK ports WDK , serial universal asynchronous receiver-transmitters WDK serial devices UART WDK serial devices function drivers WDK serial ports serial drivers WDK 16550 UART-compatible interfaces WDK serial devices lower-level device filter drivers WDK serial devices higher-level device filter drivers WDK serial devices filter drivers WDK serial devices	01/18/2023

Using Serial.sys and Serenum.sys

The following system components are available for use with serial controller devices that have hardware interfaces that are compatible with the 16550 universal asynchronous receiver-transmitter (UART):

• Serial and Serenum drivers

  Serial.sys (Serial) is a system-supplied function driver for serial devices. You can also use Serial as a lower-level device filter driver for any type of Plug and Play device that requires a 16550 UART-compatible interface.

  Serenum.sys (Serenum) is a system-supplied upper-level device filter driver that you can use in conjunction with Serial (or a vendor-supplied function driver) to provide the function of a Plug and Play bus driver for an RS-232 port.

  For more information about the operation of Serial and Serenum, see the following topics:

  • Serial Controller Drivers Overview
  • Features of Serial and Serenum
  • Configuration of Serial Devices and Drivers
  • Operation of Serenum and Serial
  • Registry Settings for Serial
  • Registry Settings for Serenum
  • Serial Driver Reference
  • Serenum Driver Reference
  • Data definitions in the Ntddser.h header file in the WDK.

• Ports device setup class

  The Ports class includes serial ports and COM ports. A serial port is a serial communication hardware interface on a 16550 UART or compatible device. An RS-232 port on a computer is typically a DB-9 or DB-25 connector that is electrically connected to the serial port on a UART. A COM port is a serial port that complies with additional Windows-specific requirements. For more information, see Configuration of COM Ports.

• COM port device interface class

  You must use a COM port device interface to access a COM port. (The GUID for the COM port device interface class is GUID_DEVINTERFACE_COMPORT.)

• COM port database and COM port database support routines

  The COM port database arbitrates the use of COM port numbers by COM ports.

For information about installing serial devices, see Installing Serial Devices.

For general information about the high-level operation of a serial device, see the information about the communications resources that are supported by the Windows Base Services in the Microsoft Windows SDK.

Serial driver samples

These samples demonstrates serial drivers.

• The Serial sample builds a function driver for serial devices.
• The Serenum sample provides Plug and Play functionality of a bus driver for an RS-232 port.
• A simple virtual serial driver (ComPort) and a controller-less modem driver (FakeModem).
  • The Virtual serial2 driver sample (KMDF)