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CZ(4) Device Drivers Manual CZ(4)

czCyclades-Z series multi-port serial adapter device

cz* at pci?

The cz device driver supports the Cyclades-Z series of multi-port serial adapters. The Cyclades-Z is an intelligent serial controller comprising:

The MIPS CPU runs firmware provided by the device driver. Communication with the MIPS is performed by modifying data structures located in board local RAM or host RAM.

The Cyclades-Z comes in three basic flavors:

The Cyclades-Z has several features to improve performance under high serial I/O load:

/dev/ttyZ??
dial-in (normal) TTY device
/dev/cuaZ??
dial-out TTY device

intro(4), pci(4), termios(4), tty(4)

The cz driver first appeared in OpenBSD 3.0.

The cz driver was written by Jason R. Thorpe <thorpej@zembu.com> and Bill Studenmund <wrstuden@zembu.com> of Zembu Labs, Inc.

The cz driver does not currently implement communication via host RAM. While this may improve performance by reducing the number of PCI memory space read/write cycles, it is not straightforward to implement with the current bus_dma(9) API.

Interrupt mode has not been tested.

There is no support for reading or writing the EEPROM connected to the PLX PCI bus controller.

March 16, 2018 OpenBSD-7.3