xref: /freebsd/share/man/man4/smbus.4 (revision 56b1692a2c22cadb632ec00d038fdeb08b4477fe)
1eb8752d5SNicolas Souchu.\" Copyright (c) 1998, Nicolas Souchu
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26eb8752d5SNicolas Souchu.Dd August 10, 1998
27eb8752d5SNicolas Souchu.Dt SMBBUS 4
28eb8752d5SNicolas Souchu.Os FreeBSD
29eb8752d5SNicolas Souchu.Sh NAME
30eb8752d5SNicolas Souchu.Nm smbus
31eb8752d5SNicolas Souchu.Nd
32eb8752d5SNicolas SouchuSystem Management Bus
33eb8752d5SNicolas Souchu.Sh SYNOPSIS
34eb8752d5SNicolas Souchu.Cd "controller smbus"
35eb8752d5SNicolas Souchu.Pp
36eb8752d5SNicolas Souchu.Cd "device iicsmb0 at iicbus?"
37eb8752d5SNicolas Souchu.Cd "device bktr0"
38eb8752d5SNicolas Souchu.Sh DESCRIPTION
39eb8752d5SNicolas SouchuThe
40eb8752d5SNicolas Souchu.Em smbus
41eb8752d5SNicolas Souchusystem provides a uniform, modular and architecture-independent
42eb8752d5SNicolas Souchusystem for the implementation of drivers to control various SMB devices
43eb8752d5SNicolas Souchuand to utilize different SMB controllers (I2C, PIIX4, Brooktree848, vm86...).
44eb8752d5SNicolas Souchu.Sh System Management Bus
45eb8752d5SNicolas SouchuThe
46eb8752d5SNicolas Souchu.Em System Management Bus
47eb8752d5SNicolas Souchuis a two-wire interface through which simple power-related chips can communicate
48eb8752d5SNicolas Souchuwith rest of the system. It uses I2C as its backbone (see
49eb8752d5SNicolas Souchu.Xr iicbus 4 ).
50eb8752d5SNicolas Souchu
51eb8752d5SNicolas SouchuA system using SMB passes messages to and from devices instead of tripping
52eb8752d5SNicolas Souchuindividual control lines.
53eb8752d5SNicolas Souchu
54eb8752d5SNicolas SouchuWith the SMBus, a device can provide manufacturer information, tell the
55eb8752d5SNicolas Souchusystem what its model/part number is, save its state for a suspend event,
56eb8752d5SNicolas Souchureport different types of errors, accept control parameters, and return its
57eb8752d5SNicolas Souchustatus.
58eb8752d5SNicolas Souchu
5956b1692aSJean-Marc ZucconiThe SMBus may share the same host device and physical bus as ACCESS bus
6056b1692aSJean-Marc Zucconicomponents provided that an appropriate electrical bridge is provided
6156b1692aSJean-Marc Zucconibetween the internal SMB devices and external ACCESS bus devices.
62eb8752d5SNicolas Souchu.Sh SEE ALSO
63eb8752d5SNicolas Souchu.Xr iicbus 4 ,
64eb8752d5SNicolas Souchu.Xr iicsmb 4 ,
65eb8752d5SNicolas Souchu.Xr bktr 4 ,
66eb8752d5SNicolas Souchu.Xr smb 4
67eb8752d5SNicolas Souchu.Sh HISTORY
68eb8752d5SNicolas SouchuThe
69eb8752d5SNicolas Souchu.Nm
70eb8752d5SNicolas Souchumanual page first appeared in
71eb8752d5SNicolas Souchu.Fx 3.0 .
72eb8752d5SNicolas Souchu.Sh AUTHOR
73eb8752d5SNicolas SouchuThis
74eb8752d5SNicolas Souchumanual page was written by
75eb8752d5SNicolas Souchu.An Nicolas Souchu .
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