Datasheet

 2011-2013 Microchip Technology Inc. DS70657G-page 285
dsPIC33EPXXXGP50X, dsPIC33EPXXXMC20X/50X AND PIC24EPXXXGP/MC20X
21.0 ENHANCED CAN (ECAN™)
MODULE (dsPIC33EPXXXGP/
MC50X DEVICES ONLY)
21.1 Overview
The Enhanced Controller Area Network (ECAN)
module is a serial interface, useful for communicat-
ing with other CAN modules or microcontroller
devices. This interface/protocol was designed to
allow communications within noisy environments.
The dsPIC33EPXXXGP/MC50X devices contain one
ECAN module.
The ECAN module is a communication controller
implementing 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 ECAN 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 data length
• Programmable bit rate up to 1 Mbit/sec
• Automatic response to remote transmission
requests
• Up to eight transmit buffers with application speci-
fied 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 (IC2) module
for time-stamping and network synchronization
• Low-power Sleep and Idle mode
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 dsPIC33EPXXXGP50X,
dsPIC33EPXXXMC20X/50X and
PIC24EPXXXGP/MC20X families of
devices. It is not intended to be a
comprehensive reference source. To
complement the information in this data
sheet, refer to Section 21. “Enhanced
Controller Area Network (ECAN™)”
(DS70353) of the “dsPIC33E/PIC24E
Family Reference Manual”, 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.