Datasheet
14.1 Block Diagram
Figure 14-1. I
2
C Block Diagram
I
2
C I/O Select
I
2
C Master Core
Interrupt
I
2
C Slave Core
I2CSCL
I2CSDA
I2CSDA
I2CSCL
I2CSDA
I2CSCL
I2CMSA
I2CMCS
I2CMDR
I2CMTPR
I2CMIMR
I2CMRIS
I2CMICR
I2CMCR
I2CSOAR
I2CSCSR
I2CSDR
I2CSIM
I2CSRIS
I2CSMIS
I2CSICRI2CMMIS
I
2
C Control
14.2 Signal Description
Table 14-1 on page 515 and Table 14-2 on page 515 list the external signals of the I
2
C interface and
describe the function of each. The I
2
C 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 I
2
C function. The column in the table below titled "Pin Assignment" lists the possible
GPIO pin placements for the I
2
C signals. The AFSEL bit in the GPIO Alternate Function Select
(GPIOAFSEL) register (page 311) should be set to choose the I
2
C function. Note that the I
2
C 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 289.
Table 14-1. I2C Signals (100LQFP)
DescriptionBuffer Type
a
Pin TypePin NumberPin Name
I
2
C module 0 clock.ODI/O70I2C0SCL
I
2
C module 0 data.ODI/O71I2C0SDA
a. The TTL designation indicates the pin has TTL-compatible voltage levels.
Table 14-2. I2C Signals (108BGA)
DescriptionBuffer Type
a
Pin TypePin NumberPin Name
I
2
C module 0 clock.ODI/OC11I2C0SCL
I
2
C module 0 data.ODI/OC12I2C0SDA
a. The TTL designation indicates the pin has TTL-compatible voltage levels.
14.3 Functional Description
The I
2
C 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 I
2
C bus configuration is shown in Figure 14-2 on page 516.
See “Inter-Integrated Circuit (I
2
C) Interface” on page 761 for I
2
C timing diagrams.
515June 18, 2012
Texas Instruments-Production Data
Stellaris
®
LM3S8962 Microcontroller
NRND: Not recommended for new designs.