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69 lines
2.0 KiB
69 lines
2.0 KiB
\section{\IIC Unit}
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The \gls{I2C} unit provides access to one of the microcontroller's \gls{I2C} peripherals. More on the \IIC bus can be found in section~\ref{sec:theory-i2c}.
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The unit can be configured to use either of the three standard speeds (Standard, Fast and Fast+) and supports both 10-bit and 7-bit addressing. 10-bit addresses can be used in commands by setting their highest bit (0x8000), as a flag to the unit; the 7 or 10 least significant bits will be used as the actual address.
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\subsection{\IIC Configuration}
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\begin{inicode}
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[I2C:d@4]
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# Peripheral number (I2Cx)
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device=1
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# Pin mappings (SCL,SDA)
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# I2C1: (0) B6,B7 (1) B8,B9
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# I2C2: (0) B10,B11 (1) B13,B14
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remap=0
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# Speed: 1-Standard, 2-Fast, 3-Fast+
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speed=1
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# Analog noise filter enable (Y,N)
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analog-filter=Y
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# Digital noise filter bandwidth (0-15)
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digital-filter=0
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\end{inicode}
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\subsection{\IIC Commands}
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\begin{cmdlist}
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0 & \cname{WRITE}
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Perform a raw write transaction
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& \begin{cmdreq}
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\cfield{u16} slave address
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\cfield{u8[]} bytes to write
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\end{cmdreq} \\
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1 & \cname{READ}
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Perform a raw read transaction.
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& \begin{cmdreq}
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\cfield{u16} slave address
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\cfield{u16} number of read bytes
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\end{cmdreq}
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\cjoin
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\begin{cmdresp}
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\cfield{u8[]} received bytes
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\end{cmdresp} \\
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2 & \cname{WRITE\_REG}
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Write to a slave register. Sends the register number and the data in the same transaction. Multiple registers can be written at once if the slave supports auto-increment.
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& \begin{cmdreq}
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\cfield{u16} slave address
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\cfield{u8} register number
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\cfield{u8[]} bytes to write
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\end{cmdreq} \\
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3 & \cname{READ\_REG}
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Read from a slave register. Writes the register number and issues a read transaction of the given length. Multiple registers can be read at once if the slave supports auto-increment.
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& \begin{cmdreq}
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\cfield{u16} slave address
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\cfield{u8} register number
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\cfield{u16} number of read bytes
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\end{cmdreq}
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\cjoin
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\begin{cmdresp}
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\cfield{u8[]} received bytes
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\end{cmdresp} \\
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\end{cmdlist}
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