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docs: i2c: i2c-protocol: properly name start and stop conditions

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In I2C there is no such thing as a "start bit" or a "stop bit". Use the
proper naming: "start condition" and "stop condition".

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This commit is contained in:
Luca Ceresoli
2020-01-29 16:19:33 +01:00
committed by Wolfram Sang
parent f72beb8bf9
commit f954731d2a
1 changed files with 8 additions and 7 deletions
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15
Documentation/i2c/i2c-protocol.rst
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@@ -8,8 +8,8 @@ Key to symbols
============== ==============
=============== ============================================================= =============== =============================================================
S (1 bit) : Start bit S : Start condition
P (1 bit) : Stop bit P : Stop condition
Rd/Wr (1 bit) : Read/Write bit. Rd equals 1, Wr equals 0. Rd/Wr (1 bit) : Read/Write bit. Rd equals 1, Wr equals 0.
A, NA (1 bit) : Accept and reverse accept bit. A, NA (1 bit) : Accept and reverse accept bit.
Addr (7 bits): I2C 7 bit address. Note that this can be expanded as usual to Addr (7 bits): I2C 7 bit address. Note that this can be expanded as usual to
@@ -46,9 +46,9 @@ Combined transactions
This corresponds to i2c_transfer(). This corresponds to i2c_transfer().
They are just like the above transactions, but instead of a stop bit P They are just like the above transactions, but instead of a stop
a start bit S is sent and the transaction continues. An example of condition P a start condition S is sent and the transaction continues.
a byte read, followed by a byte write:: An example of a byte read, followed by a byte write::
S Addr Rd [A] [Data] NA S Addr Wr [A] Data [A] P S Addr Rd [A] [Data] NA S Addr Wr [A] Data [A] P
@@ -77,8 +77,9 @@ I2C_M_NOSTART:
S Addr Rd [A] [Data] NA Data [A] P S Addr Rd [A] [Data] NA Data [A] P
If you set the I2C_M_NOSTART variable for the first partial message, If you set the I2C_M_NOSTART variable for the first partial message,
we do not generate Addr, but we do generate the startbit S. This will we do not generate Addr, but we do generate the start condition S.
probably confuse all other clients on your bus, so don't try this. This will probably confuse all other clients on your bus, so don't
try this.
This is often used to gather transmits from multiple data buffers in This is often used to gather transmits from multiple data buffers in
system memory into something that appears as a single transfer to the system memory into something that appears as a single transfer to the