Date: Mon, 7 Sep 2020 07:44:15 +0000 (UTC) From: Li-Wen Hsu <lwhsu@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r365403 - head/share/man/man4 Message-ID: <202009070744.0877iF1V082300@repo.freebsd.org>
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Author: lwhsu Date: Mon Sep 7 07:44:14 2020 New Revision: 365403 URL: https://svnweb.freebsd.org/changeset/base/365403 Log: Slightly improve usb(4) - Mention USB 3.0 - Update links - Fix `mandoc -T lint` warnings Reviewed by: bcr, hselasky MFC after: 3 days Differential Revision: https://reviews.freebsd.org/D26349 Modified: head/share/man/man4/usb.4 Modified: head/share/man/man4/usb.4 ============================================================================== --- head/share/man/man4/usb.4 Mon Sep 7 06:53:29 2020 (r365402) +++ head/share/man/man4/usb.4 Mon Sep 7 07:44:14 2020 (r365403) @@ -24,7 +24,7 @@ .\" .\" $FreeBSD$ .\" -.Dd April 24, 2018 +.Dd September 7, 2020 .Dt USB 4 .Os .Sh NAME @@ -52,8 +52,7 @@ for more information. .Sh DESCRIPTION .Fx provides machine-independent bus support and drivers for -.Tn USB -devices in host and device side mode. +USB devices in host and device side mode. .Pp The .Nm @@ -67,32 +66,25 @@ driver has three layers: The controller attaches to a physical bus like .Xr pci 4 . -The -.Tn USB -bus attaches to the controller, and the root hub attaches +The USB bus attaches to the controller, and the root hub attaches to the controller. Any devices attached to the bus will attach to the root hub -or another hub attached to the -.Tn USB -bus. +or another hub attached to the USB bus. .Pp The .Nm uhub device will always be present as it is needed for the root hub. .Sh INTRODUCTION TO USB -The -.Tn USB -is a system where external devices can be connected to a PC. +The USB is a system where external devices can be connected to a PC. The most common USB speeds are: .Bl -tag -width 6n -offset indent -.It Low Speed (1.5MBit/sec) -.It Full Speed (12MBit/sec) -.It High Speed (480MBit/sec) +.It Low Speed (1.5 MBit/sec) +.It Full Speed (12 MBit/sec) +.It High Speed (480 MBit/sec) +.It SuperSpeed (5 GBit/sec) .El .Pp -Each -.Tn USB -has a USB controller that is the master of the bus. +Each USB has a USB controller that is the master of the bus. The physical communication is simplex which means the host controller only communicates with one USB device at a time. .Pp @@ -122,9 +114,7 @@ A device may operate in different configurations. Depending on the configuration, the device may present different sets of endpoints and interfaces. .Pp -The bus enumeration of the -.Tn USB -bus proceeds in several steps: +The bus enumeration of the USB bus proceeds in several steps: .Bl -enum .It Any interface specific driver can attach to the device. @@ -144,11 +134,9 @@ debug message verbosity. Default is 0. .El .Sh SEE ALSO -The -.Tn USB -specifications can be found at: +The USB specifications can be found at: .Pp -.D1 Pa http://www.usb.org/developers/docs/ +.D1 Pa https://www.usb.org/documents .Pp .Xr libusb 3 , .Xr aue 4 , @@ -178,7 +166,7 @@ specifications can be found at: .Sh STANDARDS The .Nm -module complies with the USB 2.0 standard. +module complies with the USB 3.0 standard. .Sh HISTORY The .Nm
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