---
name: "ucycom"
section: "4"
platform: "freebsd"
package: "base"
version: "16.0-CURRENT-20261027-61c70dc16a79"
release: "FreeBSD 16.0-CURRENT (2026-10-27)"
platforms: ["linux", "freebsd", "openbsd"]
url: "https://new.carta.tech/ucycom"
---

# ucycom(4)

device driver for Cypress CY7C63743 and CY7C64013 USB to RS232 bridges

## NAME

**ucycom** – device driver for Cypress CY7C63743 and CY7C64013 USB to RS232 bridges

## SYNOPSIS

**device** **usb** **device** **hid** **device** **ucom** **device** **ucycom**

In [loader.conf(5)](/loader.conf/5.md): **ucycom\_load="YES"**

## DESCRIPTION

The **ucycom** driver provides support for the Cypress CY7C63743 and CY7C64013 bridge chips. These chips were designed to provide a low-cost transition path to USB for existing RS232 devices, and have fairly limited capabilities.

The **ucycom** driver behaves like a [tty(4)](/tty/4.md).

## HARDWARE

The **ucycom** driver currently supports the following devices which incorporate Cypress USB to RS232 bridge chips:

- DeLorme Earthmate USB GPS receiver

## FILES

- */dev/ttyU\**

  for callin ports

- */dev/ttyU\*.init*

  - */dev/ttyU\*.lock*

  corresponding callin initial-state and lock-state devices

- */dev/cuaU\**

  for callout ports

- */dev/cuaU\*.init*

  - */dev/cuaU\*.lock*

  corresponding callout initial-state and lock-state devices

## SEE ALSO

[tty(4)](/tty/4.md), [ucom(4)](/ucom/4.md), [usb(4)](/usb/4.md)

## HISTORY

The **ucycom** driver first appeared in FreeBSD 5.3.

## AUTHORS

The **ucycom** driver and this manual page were written by Dag-Erling Smørgrav ⟨*des@FreeBSD.org*⟩.