LM3S5D91 Datasheet, PDF (52/1340 Pages) Texas Instruments – Stellaris® LM3S5D91 Microcontroller

Architectural Overview
1.3.4
1.3.4.1
– Optional clock output, read/write strobes, framing (with counter-based size), and clock-enable
input
■ General parallel GPIO
– 1 to 32 bits, FIFOed with speed control
– Useful for custom peripherals or for digital data acquisition and actuator controls
Serial Communications Peripherals
The LM3S5D91 controller supports both asynchronous and synchronous serial communications
with:
■ Two CAN 2.0 A/B controllers
■ USB 2.0 OTG/Host/Device
■ Three UARTs with IrDA and ISO 7816 support (one UART with modem flow control and status)
■ Two I²C modules
■ Two Synchronous Serial Interface modules (SSI)
■ Integrated Interchip Sound (I²S) module
The following sections provide more detail on each of these communications functions.
Controller Area Network (see page 866)
Controller Area Network (CAN) is a multicast shared serial-bus standard for connecting electronic
control units (ECUs). CAN was specifically designed to be robust in electromagnetically noisy
environments and can utilize a differential balanced line like RS-485 or twisted-pair wire. Originally
created for automotive purposes, it is now used in many embedded control applications (for example,
industrial or medical). Bit rates up to 1 Mbps are possible at network lengths below 40 meters.
Decreased bit rates allow longer network distances (for example, 125 Kbps at 500m).
A transmitter sends a message to all CAN nodes (broadcasting). Each node decides on the basis
of the identifier received whether it should process the message. The identifier also determines the
priority that the message enjoys in competition for bus access. Each CAN message can transmit
from 0 to 8 bytes of user information.
The LM3S5D91 microcontroller includes two CAN units with the following features:
■ CAN protocol version 2.0 part A/B
■ Bit rates up to 1 Mbps
■ 32 message objects with individual identifier masks
■ Maskable interrupt
■ Disable Automatic Retransmission mode for Time-Triggered CAN (TTCAN) applications
■ Programmable Loopback mode for self-test operation
■ Programmable FIFO mode enables storage of multiple message objects
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January 22, 2012
Texas Instruments-Production Data