Datasheet

 2013-2014 Microchip Technology Inc. DS70000689D-page 295
dsPIC33EPXXXGM3XX/6XX/7XX
21.0 CONTROLLER AREA
NETWORK (CAN) MODULE
(dsPIC33EPXXXGM6XX/7XX
DEVICES ONLY)
21.1 Overview
The Controller Area Network (CAN) module is a serial
interface, useful for communicating with other CAN
modules or microcontroller devices. This interface/
protocol was designed to allow communications within
noisy environments. The dsPIC33EPXXXGM6XX/7XX
devices contain two CAN modules.
The CAN module is a communication controller, imple-
menting the CAN 2.0 A/B protocol, as defined in the
BOSCH CAN specification. The module supports
CAN 1.2, CAN 2.0A, CAN 2.0B Passive and CAN 2.0B
Active versions of the protocol. The module implemen-
tation is a full CAN system. The CAN specification is
not covered within this data sheet. The reader can refer
to the BOSCH CAN specification for further details.
The CAN module features are as follows:
• Implementation of the CAN protocol, CAN 1.2,
CAN2.0A and CAN2.0B
• Standard and Extended Data Frames
• 0-8 Bytes of Data Length
• Programmable Bit Rate, up to 1 Mbit/sec
• Automatic Response to Remote Transmission
Requests
• Up to 8 Transmit Buffers with Application
Specified Prioritization and Abort Capability (each
buffer can contain up to 8 bytes of data)
• Up to 32 Receive Buffers (each buffer can contain
up to 8 bytes of data)
• Up to 16 Full (Standard/Extended Identifier)
Acceptance Filters
• Three Full Acceptance Filter Masks
• DeviceNet™ Addressing Support
• Programmable Wake-up Functionality with
Integrated Low-Pass Filter
• Programmable Loopback mode supports
Self-Test Operation
• Signaling via Interrupt Capabilities for all CAN
Receiver and Transmitter Error States
• Programmable Clock Source
• Programmable Link to Input Capture 2 (IC2)
module for Timestamping and Network
Synchronization
• Low-Power Sleep and Idle modes
The CAN bus module consists of a protocol engine and
message buffering/control. The CAN protocol engine
handles all functions for receiving and transmitting
messages on the CAN bus. Messages are transmitted
by first loading the appropriate data registers. Status
and errors can be checked by reading the appropriate
registers. Any message detected on the CAN bus is
checked for errors and then matched against filters to
see if it should be received and stored in one of the
receive registers.
Note 1: This data sheet summarizes the features
of the dsPIC33EPXXXGM3XX/6XX/7XX
family of devices. It is not intended to be a
comprehensive reference source. To com-
plement the information in this data sheet,
refer to the “dsPIC33/PIC24 Family
Reference Manual”, “Enhanced Control-
ler Area Network (ECAN™)” (DS70353),
which is available from the Microchip
web site (www.microchip.com).
2: Some registers and associated bits
described in this section may not be
available on all devices. Refer to
Section 4.0 “Memory Organization” in
this data sheet for device-specific register
and bit information.