LM3S1439_16 Datasheet, PDF (508/699 Pages) Texas Instruments – Stellaris LM3S1439 Microcontroller

Inter-Integrated Circuit (I²C) Interface
14.1 Block Diagram
Figure 14-1. I²C Block Diagram
Interrupt
I²C Control
I2CMSA
I2CMCS
I2CMDR
I2CMTPR
I2CMIMR
I2CMRIS
I2CMMIS
I2CMICR
I2CMCR
I2CSOAR
I2CSCSR
I2CSDR
I2CSIM
I2CSRIS
I2CSMIS
I2CSICR
I²C Master Core
I2CSCL
I2CSDA
I²C Slave Core
I2CSCL
I2CSDA
I²C I/O Select
I2CSCL
I2CSDA
14.2
Signal Description
Table 14-1 on page 508 and Table 14-2 on page 508 list the external signals of the I²C interface and
describe the function of each. The I²C interface signals are alternate functions for some GPIO signals
and default to be GPIO signals at reset., with the exception of the I2C0SCL and I2CSDA pins which
default to the I²C function. The column in the table below titled "Pin Assignment" lists the possible
GPIO pin placements for the I²C signals. The AFSEL bit in the GPIO Alternate Function Select
(GPIOAFSEL) register (page 304) should be set to choose the I²C function. Note that the I²C pins
should be set to open drain using the GPIO Open Drain Select (GPIOODR) register. For more
information on configuring GPIOs, see “General-Purpose Input/Outputs (GPIOs)” on page 281.
Table 14-1. I2C Signals (100LQFP)
Pin Name
I2C0SCL
I2C0SDA
Pin Number
70
71
Pin Type
I/O
I/O
Buffer Type^a Description
OD
I²C module 0 clock.
OD
I²C module 0 data.
a. The TTL designation indicates the pin has TTL-compatible voltage levels.
Table 14-2. I2C Signals (108BGA)
Pin Name
I2C0SCL
I2C0SDA
Pin Number
C11
C12
Pin Type
I/O
I/O
Buffer Type^a Description
OD
I²C module 0 clock.
OD
I²C module 0 data.
a. The TTL designation indicates the pin has TTL-compatible voltage levels.
14.3
Functional Description
The I²C module is comprised of both master and slave functions which are implemented as separate
peripherals. For proper operation, the SDA and SCL pins must be connected to bi-directional
open-drain pads. A typical I²C bus configuration is shown in Figure 14-2 on page 509.
See “Inter-Integrated Circuit (I²C) Interface” on page 656 for I²C timing diagrams.
508
July 15, 2014
Texas Instruments-Production Data