14.2 Configuring Device Pins
The GPIO mux registers must be configured to connect this peripheral to the device pins.
Some IO functionality is defined by GPIO register settings independent of this peripheral. For input signals, the
GPIO input qualification should be set to asynchronous mode by setting the appropriate GPxQSELn register bits
to 11b. The internal pullups can be configured in the GPyPUD register.
See the
GPIO
chapter for more details on GPIO mux and settings.
14.3 I2C Module Operational Details
This section provides an overview of the I2C bus protocol and how it is implemented.
14.3.1 Input and Output Voltage Levels
One clock pulse is generated by the master device for each data bit transferred. Due to a variety of different
technology devices that can be connected to the I2C bus, the levels of logic 0 (low) and logic 1 (high) are not
fixed and depend on the associated level of V
DD
. For details, see your device-specific data sheet.
14.3.2 Data Validity
The data on SDA must be stable during the high period of the clock (see
). The high or low state of
the data line, SDA, should change only when the clock signal on SCL is low.
Data line
stable data
Change of data
allowed
SDA
SCL
Figure 14-5. Bit Transfer on the I2C bus
14.3.3 Operating Modes
The I2C module has four basic operating modes to support data transfers as a master and as a slave. See
for the names and descriptions of the modes.
If the I2C module is a master, it begins as a master-transmitter and typically transmits an address for a particular
slave. When giving data to the slave, the I2C module must remain a master-transmitter. To receive data from a
slave, the I2C module must be changed to the master-receiver mode.
If the I2C module is a slave, it begins as a slave-receiver and typically sends acknowledgment when it
recognizes its slave address from a master. If the master will be sending data to the I2C module, the module
must remain a slave-receiver. If the master has requested data from the I2C module, the module must be
changed to the slave-transmitter mode.
Inter-Integrated Circuit Module (I2C)
SPRUH18I – JANUARY 2011 – REVISED JUNE 2022
TMS320x2806x Microcontrollers
839
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Summary of Contents for TMS320 2806 Series
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