LM3S1636 Datasheet, PDF (45/656 Pages) Texas Instruments – ARM and Thumb are registered trademarks and Cortex is a trademark

OBSOLETE: TI has discontinued production of this device.
Stellaris^® LM3S1636 Microcontroller
1.4.4.2
1.4.4.3
1.4.5
1.4.5.1
SSI (see page 465)
Synchronous Serial Interface (SSI) is a four-wire bi-directional full and low-speed communications
interface.
The LM3S1636 controller includes two SSI modules that provide the functionality for synchronous
serial communications with peripheral devices, and can be configured to use the Freescale SPI,
MICROWIRE, or TI synchronous serial interface frame formats. The size of the data frame is also
configurable, and can be set between 4 and 16 bits, inclusive.
Each SSI module performs serial-to-parallel conversion on data received from a peripheral device,
and parallel-to-serial conversion on data transmitted to a peripheral device. The TX and RX paths
are buffered with internal FIFOs, allowing up to eight 16-bit values to be stored independently.
Each SSI module can be configured as either a master or slave device. As a slave device, the SSI
module can also be configured to disable its output, which allows a master device to be coupled
with multiple slave devices.
Each SSI module also includes a programmable bit rate clock divider and prescaler to generate the
output serial clock derived from the SSI module's input clock. Bit rates are generated based on the
input clock and the maximum bit rate is determined by the connected peripheral.
I²C (see page 503)
The Inter-Integrated Circuit (I²C) bus provides bi-directional data transfer through a two-wire design
(a serial data line SDA and a serial clock line SCL).
The I²C bus interfaces to external I²C devices such as serial memory (RAMs and ROMs), networking
devices, LCDs, tone generators, and so on. The I²C bus may also be used for system testing and
diagnostic purposes in product development and manufacture.
The LM3S1636 controller includes two I²C modules that provide the ability to communicate to other
IC devices over an I²C bus. The I²C bus supports devices that can both transmit and receive (write
and read) data.
Devices on the I²C bus can be designated as either a master or a slave. Each I²C module supports
both sending and receiving data as either a master or a slave, and also supports the simultaneous
operation as both a master and a slave. The four I²C modes are: Master Transmit, Master Receive,
Slave Transmit, and Slave Receive.
A Stellaris I²C module can operate at two speeds: Standard (100 Kbps) and Fast (400 Kbps).
Both the I²C master and slave can generate interrupts. The I²C master generates interrupts when
a transmit or receive operation completes (or aborts due to an error). The I²C slave generates
interrupts when data has been sent or requested by a master.
System Peripherals
Programmable GPIOs (see page 280)
General-purpose input/output (GPIO) pins offer flexibility for a variety of connections.
The Stellaris GPIO module is comprised of eight physical GPIO blocks, each corresponding to an
individual GPIO port. The GPIO module is FiRM-compliant (compliant to the ARM Foundation IP
for Real-Time Microcontrollers specification) and supports 12-56 programmable input/output pins.
The number of GPIOs available depends on the peripherals being used (see “Signal
Tables” on page 592 for the signals available to each GPIO pin).
July 24, 2012
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Texas Instruments-Production Data