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Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/i2c/summary.rst | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/Documentation/i2c/summary.rst b/Documentation/i2c/summary.rst index 786c618ba3be..28ff80a2302b 100644 --- a/Documentation/i2c/summary.rst +++ b/Documentation/i2c/summary.rst @@ -4,10 +4,10 @@ Introduction to I2C and SMBus I²C (pronounce: I squared C and written I2C in the kernel documentation) is a protocol developed by Philips. It is a slow two-wire protocol (variable -speed, up to 400 kHz), with a high speed extension (3.4 MHz). It provides +speed, up to 400 kHz), with a high speed extension (3.4 MHz). It provides an inexpensive bus for connecting many types of devices with infrequent or -low bandwidth communications needs. I2C is widely used with embedded -systems. Some systems use variants that don't meet branding requirements, +low bandwidth communications needs. I2C is widely used with embedded +systems. Some systems use variants that don't meet branding requirements, and so are not advertised as being I2C but come under different names, e.g. TWI (Two Wire Interface), IIC. @@ -18,14 +18,14 @@ access the PDF. An older version of the specification (revision 6) is archived `here <https://web.archive.org/web/20210813122132/https://www.nxp.com/docs/en/user-guide/UM10204.pdf>`_. SMBus (System Management Bus) is based on the I2C protocol, and is mostly -a subset of I2C protocols and signaling. Many I2C devices will work on an +a subset of I2C protocols and signaling. Many I2C devices will work on an SMBus, but some SMBus protocols add semantics beyond what is required to -achieve I2C branding. Modern PC mainboards rely on SMBus. The most common +achieve I2C branding. Modern PC mainboards rely on SMBus. The most common devices connected through SMBus are RAM modules configured using I2C EEPROMs, and hardware monitoring chips. Because the SMBus is mostly a subset of the generalized I2C bus, we can -use its protocols on many I2C systems. However, there are systems that don't +use its protocols on many I2C systems. However, there are systems that don't meet both SMBus and I2C electrical constraints; and others which can't implement all the common SMBus protocol semantics or messages. |