CZ(4) | Device Drivers Manual | CZ(4)

# NAME

`cz` — Cyclades-Z series multi-port serial adapter device

# SYNOPSIS

`cz* at pci?`

# DESCRIPTION

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

- PLX9060ES PCI bus interface
- Xilinx XC5204 FPGA
- IDT R3052 MIPS CPU

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:

- Cyclades-8Zo rev. 1 — This is an older 8-port board with no FPGA. The serial ports are provided by an octopus cable.
- Cyclades-8Zo rev. 2 — This is the newer 8-port board. The serial ports are provided by an octopus cable.
- Cyclades-Ze — This is the expandable version of the Cyclades-Z. It uses an HD-50 SCSI cable to connect the board to a 1U rack mountable serial expansion box. Each box has 16 RJ45 serial ports, and up to 4 boxes may be chained together, for a total of 64 ports. Boxes 3 and 4 require their own external power supply, otherwise the firmware will refuse to start (as it cannot communicate with the UARTs in those boxes).

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

- The board may operate in interrupt-driven mode or polled mode to reduce interrupt load.
- Each channel has a large input and output buffer.
- Each channel may be programmed to generate an interrupt based on reception of a specific character, e.g. a PPP End-Of-Frame character.
- The MIPS CPU on the board performs all flow-control handling.

# FILES

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

# SEE ALSO

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

# HISTORY

The `cz` driver first appeared in OpenBSD 3.0.

# AUTHORS

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

# BUGS

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 | Debian