DESCRIPTION
atppc supports parallel ports and provides the low level support needed by higher level drivers such as
ppbus(4). This driver attaches where the traditional
NetBSD lpt(4) driver would ordinarily. It provides the data transport and chip set manipulation needed by higher driver layers, such as
ppbus(4) and
lpt(4). This driver is designed to be one of many possible implementations supporting machine independent parallel device support via
ppbus(4).
IEEE 1284 support
atppc is intended to provide to data-link like services to higher level IEEE 1284 device drivers (such as
ppbus(4)).
atppc does not directly support IEEE 1284 features such as mode negotiation but rather provides the necessary infrastructure to allow a higher level driver to provide these services.
atppc does provide chip set manipulation, device handshakes (where appropriate), low-level error detection, and data transfer.
Supported data transfer modes
atppc supports the following data transfer modes: Centronics Compatible (Standard), Nibble, Byte (PS2), Fast Centronics, ECP, and EPP. Standard and Fast Centronics modes are write only, Nibble and Byte modes are read only, and ECP and EPP modes are bidirectional.