LM3S5956-IQR80-C1 Datasheet, PDF (711/1144 Pages) Texas Instruments – Stellaris® LM3S5956 Microcontroller

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Stellaris^® LM3S5956 Microcontroller
15.1 Block Diagram
Figure 15-1. I²C Block Diagram
Interrupt
I²C Control
I2CMSA
I2CMCS
I2CMDR
I2CMTPR
I2CMIMR
I2CMRIS
I2CMMIS
I2CMICR
I2CMCR
I2CSOAR
I2CSCSR
I2CSDR
I2CSIMR
I2CSRIS
I2CSMIS
I2CSICR
I²C Master Core
I2CSCL
I2CSDA
I²C Slave Core
I2CSCL
I2CSDA
I²C I/O Select
I2CSCL
I2CSDA
15.2
Signal Description
The following table lists the external signals of the I²C interface and describes 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 Mux/Pin Assignment" lists the possible GPIO pin
placements for the I²C signals. The AFSEL bit in the GPIO Alternate Function Select (GPIOAFSEL)
register (page 431) should be set to choose the I²C function. The number in parentheses is the
encoding that must be programmed into the PMCn field in the GPIO Port Control (GPIOPCTL)
register (page 448) to assign the I²C signal to the specified GPIO port pin. 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 411.
Table 15-1. I2C Signals (64LQFP)
Pin Name
I2C0SCL
I2C0SDA
I2C1SCL
I2C1SDA
Pin Number Pin Mux / Pin
Assignment
47
PB2 (1)
27
PB3 (1)
17
PA0 (8)
25
PA6 (1)
18
PA1 (8)
26
PA7 (1)
Pin Type
I/O
I/O
I/O
I/O
Buffer Type^a Description
OD
I²C module 0 clock.
OD
I²C module 0 data.
OD
I²C module 1 clock.
OD
I²C module 1 data.
a. The TTL designation indicates the pin has TTL-compatible voltage levels.
15.3
Functional Description
Each I²C module is comprised of both master and slave functions. For proper operation, the SDA
and SCL pins must be configured as open-drain signals. A typical I²C bus configuration is shown
in Figure 15-2.
See “Inter-Integrated Circuit (I²C) Interface” on page 1082 for I²C timing diagrams.
October 06, 2012
711
Texas Instruments-Production Data