MDK-ARM Keil, MDK-ARM Datasheet - Page 141

• Manufacturer Part Number: MDK-ARM
• Description: KIT REALVIEW MCU DEVELOPMENT
• Manufacturer: Keil
• Type: Compiler and IDEr

Specifications of MDK-ARM

• For Use With/related Products: ARM MCUs
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Getting Started: Building Applications with RL-ARM
Chapter 6. RL-CAN Introduction
The CAN (Controller Area Network) protocol was originally developed for
networking in the automotive sector. The aim was to replace the wiring loom in
passenger vehicles. CAN is characterized by relatively fast data transfer, good
error detection, good recovery and low electromagnetic interference (EMI).
Unlike Ethernet, its arbitration method can guarantee deterministic delivery of
message packets within defined system latency. It has been widely adopted into
many industries as a de-facto standard for distributed control systems, as it is an
ideal method of networking small, embedded systems. This chapter examines
the RL-CAN driver, which allows you to rapidly and easily build a CAN network
with many different manufacturers’ CAN controller peripherals.
The CAN Protocol – Key Concepts
In the ISO 7-layer model, the
CAN protocol covers the layer
two, ”Data Link Layer”. This
involves forming the message
packet, error containment,
acknowledgement, and
arbitration.
CAN does not rigidly define
layer one “Physical Layer”. This
means, that CAN messages may
use many different physical
mediums. However, the most
common physical layer is a
twisted pair, and standard line
drivers are available for it. In a CAN network, the other layers in the ISO model
are effectively empty, and your application code will communicate directly to the
data link layer.
The application code addresses the registers of the CAN peripheral directly. In
effect, the CAN peripheral can be used as a glorified UART, without the need for
an expensive and complex protocol stack. Since CAN is also used in Industrial
Automation, there are a number of software standards defining how the CAN
messages are used. This is necessary in order to transfer data between different
manufacturers’ equipment.
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