Texas Instruments TMS320x281 series User manual

TMS320x281x

Enhanced Controller Area Network (eCAN)

Reference Guide

Literature Number: SPRU074FMay 2002 – Revised January 2009

2 SPRU074F – May 2002 – Revised January 2009Submit Documentation Feedback

Contents
Preface ............................................................................................................................... 7
1 Architecture ............................................................................................................... 91.1 CAN Overview .............................................................................................................. 101.1.1 Features ............................................................................................................ 101.1.2 Block Diagram ..................................................................................................... 111.1.3 eCAN Compatibility With Other TI CAN Modules ............................................................. 111.2 The CAN Network and Module ........................................................................................... 121.2.1 CAN Protocol Overview .......................................................................................... 121.3 eCAN Controller Overview ................................................................................................ 131.3.1 Standard CAN Controller (SCC) Mode ......................................................................... 141.3.2 Memory Map ....................................................................................................... 151.3.3 eCAN Control and Status Registers ............................................................................ 181.4 Message Objects ........................................................................................................... 191.5 Message Mailbox ........................................................................................................... 191.5.1 Transmit Mailbox .................................................................................................. 231.5.2 Receive Mailbox ................................................................................................... 241.5.3 CAN Module Operation in Normal Configuration.............................................................. 24
2 eCAN Registers ........................................................................................................ 252.1 Mailbox Enable Register (CANME) ...................................................................................... 262.2 Mailbox-Direction Register (CANMD) .................................................................................... 272.3 Transmission-Request Set Register (CANTRS) ....................................................................... 282.4 Transmission-Request-Reset Register (CANTRR) .................................................................... 292.5 Transmission-Acknowledge Register (CANTA) ........................................................................ 302.6 Abort-Acknowledge Register (CANAA) .................................................................................. 312.7 Received-Message-Pending Register (CANRMP) ..................................................................... 322.8 Received-Message-Lost Register (CANRML) .......................................................................... 332.9 Remote-Frame-Pending Register (CANRFP) .......................................................................... 342.9.1 Handling of Remote Frames ..................................................................................... 342.10 Global Acceptance Mask Register (CANGAM)......................................................................... 362.11 Master Control Register (CANMC) ....................................................................................... 372.11.1 CAN Module Action in SUSPEND ............................................................................. 392.12 Bit-Timing Configuration Register (CANBTC) .......................................................................... 402.13 Error and Status Register (CANES) ..................................................................................... 422.14 CAN Error Counter Registers (CANTEC/CANREC) ................................................................... 442.15 Interrupt Registers.......................................................................................................... 452.15.1 Global Interrupt Flag Registers (CANGIF0/CANGIF1) ...................................................... 452.15.2 Global Interrupt Mask Register (CANGIM) .................................................................... 482.15.3 Mailbox Interrupt Mask Register (CANMIM) .................................................................. 502.15.4 Mailbox Interrupt Level Register (CANMIL) ................................................................... 512.16 Overwrite Protection Control Register (CANOPC) ..................................................................... 522.17 eCAN I/O Control Registers (CANTIOC, CANRIOC) .................................................................. 53
SPRU074F – May 2002 – Revised January 2009 Contents 3Submit Documentation Feedback

www.ti.com
2.18 Timer Management Unit ................................................................................................... 552.18.1 Time Stamp Functions ........................................................................................... 552.18.2 Time-Out Functions .............................................................................................. 582.18.3 Behavior/Usage of MTOF0/1 Bit in User Applications....................................................... 602.19 Mailbox Layout .............................................................................................................. 612.19.1 Message Identifier Register (MSGID) ......................................................................... 612.19.2 CPU Mailbox Access ............................................................................................ 622.19.3 Message-Control Register (MSGCTRL)....................................................................... 632.19.4 Message Data Registers (CANMDL, CANMDH) ............................................................. 642.20 Acceptance Filter ........................................................................................................... 652.20.1 Local-Acceptance Masks (CANLAM) .......................................................................... 65
3 eCAN Configuration .................................................................................................. 673.1 CAN Module Initialization.................................................................................................. 683.1.1 CAN Bit-Timing Configuration ................................................................................... 693.1.2 CAN Bit Rate Calculation ........................................................................................ 693.1.3 Bit Configuration Parameters for 150-MHz CAN Clock ...................................................... 703.1.4 Bit Configuration Parameters for 100-MHz CAN Clock ...................................................... 713.1.5 EALLOW Protection ............................................................................................... 723.2 Steps to Configure eCAN ................................................................................................. 723.2.1 Configuring a Mailbox for Transmit ............................................................................. 733.2.2 Transmitting a Message .......................................................................................... 733.2.3 Configuring Mailboxes for Receive.............................................................................. 733.2.4 Receiving a Message ............................................................................................. 743.2.5 Handling of Overload Situations ................................................................................. 743.3 Handling of Remote Frame Mailboxes .................................................................................. 743.3.1 Requesting Data From Another Node .......................................................................... 743.3.2 Answering a Remote Request ................................................................................... 753.3.3 Updating the Data Field .......................................................................................... 753.4 Interrupts .................................................................................................................... 753.4.1 Interrupts Scheme ................................................................................................. 773.4.2 Mailbox Interrupt ................................................................................................... 773.4.3 Interrupt Handling ................................................................................................. 783.5 CAN Power-Down Mode .................................................................................................. 803.5.1 Entering and Exiting Local Power-Down Mode ............................................................... 803.5.2 Precautions for Entering and Exiting Device Low-Power Modes (LPM) ................................... 803.5.3 Enabling/Disabling Clock to the CAN Module ................................................................. 813.5.4 Possible Failure Modes External to the CAN Controller Module ............................................ 81
A Revision History ....................................................................................................... 83
Contents 4 SPRU074F – May 2002 – Revised January 2009Submit Documentation Feedback

www.ti.com
List of Figures
1-1 eCAN Block Diagram and Interface Circuit ............................................................................. 111-2 CAN Data Frame ........................................................................................................... 121-3 Architecture of the eCAN Module ........................................................................................ 131-4 eCAN-A Memory Map ..................................................................................................... 161-5 eCAN-B Memory Map ..................................................................................................... 172-1 Mailbox-Enable Register (CANME) ...................................................................................... 262-2 Mailbox-Direction Register (CANMD) .................................................................................... 272-3 Transmission-Request Set Register (CANTRS) ....................................................................... 282-4 Transmission-Request-Reset Register (CANTRR) .................................................................... 292-5 Transmission-Acknowledge Register (CANTA) ........................................................................ 302-6 Abort-Acknowledge Register (CANAA) .................................................................................. 312-7 Received-Message-Pending Register (CANRMP) ..................................................................... 322-8 Received-Message-Lost Register (CANRML) .......................................................................... 332-9 Remote-Frame-Pending Register (CANRFP) .......................................................................... 342-10 Global Acceptance Mask Register (CANGAM)......................................................................... 362-11 Master Control Register (CANMC) ....................................................................................... 372-12 Bit-Timing Configuration Register (CANBTC) .......................................................................... 402-13 Error and Status Register (CANES) ..................................................................................... 422-14 Transmit-Error-Counter Register (CANTEC) ........................................................................... 442-15 Receive-Error-Counter Register (CANREC) ............................................................................ 442-16 Global Interrupt Flag 0 Register (CANGIF0) ............................................................................ 462-17 Global Interrupt Flag 1 Register (CANGIF1) ............................................................................ 462-18 Global Interrupt Mask Register (CANGIM) .............................................................................. 482-19 Mailbox Interrupt Mask Register (CANMIM) ............................................................................ 502-20 Mailbox Interrupt Level Register (CANMIL) ............................................................................. 512-21 Overwrite Protection Control Register (CANOPC) ..................................................................... 522-22 TX I/O Control Register (CANTIOC) ..................................................................................... 532-23 RX I/O Control Register (CANRIOC) .................................................................................... 542-24 Time-Stamp Counter Register (CANTSC) .............................................................................. 562-25 Message Object Time Stamp Registers (MOTS) ...................................................................... 572-26 Message-Object Time-Out Registers (MOTO) ......................................................................... 582-27 Time-Out Control Register (CANTOC) .................................................................................. 592-28 Time-Out Status Register (CANTOS) ................................................................................... 602-29 Message Identifier Register (MSGID) Register......................................................................... 612-30 Message-Control Register (MSGCTRL) ................................................................................. 632-31 Message-Data-Low Register With DBO = 0 (CANMDL) .............................................................. 642-32 Message-Data-High Register With DBO = 0 (CANMDH) ............................................................. 642-33 Message-Data-Low Register With DBO = 1 (CANMDL) .............................................................. 642-34 Message-Data-High Register With DBO = 1 (CANMDH) ............................................................. 642-35 Local-Acceptance-Mask Register (LAM n).............................................................................. 663-1 Initialization Sequence ..................................................................................................... 683-2 CAN Bit Timing ............................................................................................................. 693-3 Interrupts Scheme .......................................................................................................... 76
SPRU074F – May 2002 – Revised January 2009 List of Figures 5Submit Documentation Feedback

www.ti.com

List of Tables

1-1 Register Map ................................................................................................................ 181-2 eCAN-A Mailbox RAM Layout ............................................................................................ 201-3 Addresses of LAM, MOTS and MOTO registers for mailboxes (eCAN-A) ......................................... 211-4 eCAN-B Mailbox Ram Layout ............................................................................................ 221-5 Addresses of LAM, MOTS, and MOTO Registers for Mailboxes (eCAN-B) ........................................ 231-6 Message Object Behavior Configuration ................................................................................ 232-1 Mailbox-Enable Register (CANME) Field Descriptions ................................................................ 262-2 Mailbox-Direction Register (CANMD) Field Descriptions ............................................................. 272-3 Transmission-Request Set Register (CANTRS) Field Descriptions ................................................. 282-4 Transmission-Request-Reset Register (CANTRR) Field Descriptions .............................................. 292-5 Transmission-Acknowledge Register (CANTA) Field Descriptions .................................................. 302-6 Abort-Acknowledge Register (CANAA) Field Descriptions ........................................................... 312-7 Received-Message-Pending Register (CANRMP) Field Descriptions .............................................. 322-8 Received-Message-Lost Register (CANRML) Field Descriptions.................................................... 332-9 Remote-Frame-Pending Register (CANRFP) Field Descriptions .................................................... 342-10 Global Acceptance Mask Register (CANGAM) Field Descriptions .................................................. 362-11 Master Control Register (CANMC) Field Descriptions ................................................................ 372-12 Bit-Timing Configuration Register (CANBTC) Field Descriptions .................................................... 402-13 Error and Status Register (CANES) Field Descriptions ............................................................... 422-14 Global Interrupt Flag Registers (CANGIF0/CANGIF1) Field Descriptions .......................................... 472-15 Global Interrupt Mask Register (CANGIM) Field Descriptions ....................................................... 482-16 Mailbox Interrupt Mask Register (CANMIM) Field Descriptions ...................................................... 502-17 Mailbox Interrupt Level Register (CANMIL) Field Descriptions ...................................................... 512-18 Overwrite Protection Control Register (CANOPC) Field Descriptions .............................................. 522-19 TX I/O Control Register (CANTIOC) Field Descriptions .............................................................. 532-20 RX I/O Control Register (CANRIOC) Field Descriptions .............................................................. 542-21 Time-Stamp Counter Register (CANTSC) Field Descriptions ........................................................ 562-22 Message Object Time Stamp Registers (MOTS) Field Descriptions ................................................ 572-23 Message-Object Time-Out Registers (MOTO) Field Descriptions ................................................... 582-24 Time-Out Control Register (CANTOC) Field Descriptions ............................................................ 592-25 Time-Out Status Register (CANTOS) Field Descriptions ............................................................. 602-26 Message Identifier Register (MSGID) Field Descriptions ............................................................. 612-27 Message-Control Register (MSGCTRL) Field Descriptions .......................................................... 632-28 Local-Acceptance-Mask Register (LAM n) Field Descriptions ........................................................ 663-1 BRP Field for Bit Rates (BT = 15, TSEG1

reg

= 10, TSEG2

reg

= 2, Sampling Point = 80%) ...................... 703-2 Achieving Different Sampling Points With a BT of 15 ................................................................. 703-3 BRP Field for Bit Rates (BT = 10, TSEG1

reg

= 6, TSEG2

reg

= 1, Sampling Point = 80%) ........................ 703-4 BRP Field for Bit Rates (BT = 10, TSEG1

reg

= 6, TSEG2

reg

= 1, Sampling Point = 80%) ........................ 713-5 Achieving Different Sampling Points With a BT of 20 ................................................................. 713-6 BRP Field for Bit Rates .................................................................................................... 713-7 eCAN Interrupt Assertion/Clearing ....................................................................................... 78A-1 Changes Made in This Revision ......................................................................................... 83

List of Tables6 SPRU074F – May 2002 – Revised January 2009Submit Documentation Feedback

PrefaceSPRU074F – May 2002 – Revised January 2009

Read This First

About This Manual

This document describes the enhanced controller area network (eCAN) on the x281x device.

Notational Conventions

This document uses the following conventions.•Hexadecimal numbers are shown with the suffix h. For example, the following number is 40hexadecimal (decimal 64): 40h.

Related Documentation From Texas Instruments

The following documents describe the x281x device and related peripherals. Copies of these documentsare available for downloading at www.ti.com .

CPU User's Guides—SPRU430— TMS320C28x DSP CPU and Instruction Set Reference Guide describes the centralprocessing unit (CPU) and the assembly language instructions of the TMS320C28x fixed-pointdigital signal processors (DSPs). It also describes emulation features available on these DSPs.

SPRU078— TMS320x281x System Control and Interrupts Reference Guide describes the variousinterrupts and system control features of the 281x digital signal processors (DSPs).

Peripheral Guides—SPRU566— TMS320x28xx, 28xxx DSP Peripheral Reference Guide describes the peripheral referenceguides of the 28x digital signal processors (DSPs).

SPRU060— TMS320x281x Analog-to-Digital Converter (ADC) Reference Guide describes the ADCmodule, which is a 12-bit pipelined ADC. The analog circuits of this converter, referred to as thecore in this document, include the front-end analog multiplexers (MUXs), sample-and-hold (S/H)circuits, the conversion core, voltage regulators, and other analog supporting circuits. Digitalcircuits, referred to as the wrapper in this document, include programmable conversion sequencer,result registers, interface to analog circuits, interface to device peripheral bus, and interface to otheron-chip modules.

SPRU065— TMS320x281x Event Manager (EV) Reference Guide describes the EV modules that providea broad range of functions and features that are particularly useful in motion control and motorcontrol applications. The EV modules include general-purpose (GP) timers, full-compare/pulsewidth modulator (PWM) units, capture units, and quadrature-encoder pulse (QEP) circuits.

SPRU074— TMS320x28xx, 28xxx Enhanced Controller Area Network (eCAN) Reference Guide describesthe eCAN that uses established protocol to communicate serially with other controllers in electricallynoisy environments.

SPRU051— TMS320x28xx, 28xxx Serial Communication Interface (SCI) Reference Guide describes theSCI, which is a two-wire asynchronous serial port, commonly known as a UART. The SCI modulessupport digital communications between the CPU and other asynchronous peripherals that use thestandard non-return-to-zero (NRZ) format.

SPRU074F – May 2002 – Revised January 2009 Read This First 7Submit Documentation Feedback

Related Documentation From Texas Instruments

www.ti.com

SPRU059— TMS320x28xx, 28xxx Serial Peripheral Interface (SPI) Reference Guide describes the SPI -a high-speed synchronous serial input/output (I/O) port - that allows a serial bit stream ofprogrammed length (one to sixteen bits) to be shifted into and out of the device at a programmedbit-transfer rate.

SPRU061— TMS320x281x Multi-channel Buffered Serial Ports (McBSPs) Reference Guide describes theMcBSP available on the C28x devices. The McBSPs allow direct interface between a DSP andother devices in a system.

SPRU067— TMS320x281x External Interface (XINTF) Reference Guide describes the external interface(XINTF) of the 281x digital signal processors (DSPs).

SPRU095— TMS320x281x Boot ROM Reference Guide describes the purpose and features of thebootloader (factory-programmed boot-loading software). It also describes other contents of thedevice on-chip boot ROM and identifies where all of the information is located within that memory.

Tools Guides—

SPRU513— TMS320C28x Assembly Language Tools User's Guide describes the assembly languagetools (assembler and other tools used to develop assembly language code), assembler directives,macros, common object file format, and symbolic debugging directives for the TMS320C28x device.

SPRU514— TMS320C28x Optimizing C Compiler User's Guide describes the TMS320C28x™ C/C++compiler. This compiler accepts ANSI standard C/C++ source code and produces TMS320 DSPassembly language source code for the TMS320C28x device.

SPRU608— The TMS320C28x Instruction Set Simulator Technical Overview describes the simulator,available within the Code Composer Studio for TMS320C2000 IDE, that simulates the instructionset of the C28x™ core.

SPRU625— TMS320C28x DSP/BIOS Application Programming Interface (API) Reference Guidedescribes development using DSP/BIOS.

Read This First8 SPRU074F – May 2002 – Revised January 2009Submit Documentation Feedback

Chapter 1SPRU074F – May 2002 – Revised January 2009

Architecture

The enhanced Controller Area Network (eCAN) module implemented in the C28x™ DSP is a full-CANcontroller and is compatible with the CAN 2.0B standard (active). It uses established protocol tocommunicate serially with other controllers in electrically noisy environments. With 32 fully configurablemailboxes and time–stamping feature, the eCAN module provides a versatile and robust serialcommunication interface.

The eCAN module described in this reference guide is a Type 0 eCAN. Refer to theTMS320x28xx, 28xxxDSP Peripheral Reference Guide (SPRU566 ) for a list of other devices with a eCAN module of the sametype, to determine the differences between types, and for a list of device-specific differences within a type.Some devices have a second CAN module, eCAN-B. The word eCAN is generically used to refer to theCAN modules. The specific module reference (A or B) is used where appropriate. For a given CANmodule, the same address space is used for the module registers in all 28xx /28xxx devices.

Topic .................................................................................................. Page

1.1 CAN Overview .......................................................................... 101.2 The CAN Network and Module .................................................... 121.3 eCAN Controller Overview ......................................................... 131.4 Message Objects....................................................................... 191.5 Message Mailbox ...................................................................... 19

SPRU074F – May 2002 – Revised January 2009 Architecture 9Submit Documentation Feedback

1.1 CAN Overview

1.1.1 Features

CAN Overview

www.ti.com

Figure 1–1 shows the major blocks of the eCAN and the interface circuits.

The eCAN module has the following features:•Fully compliant with CAN protocol, version 2.0B•Supports data rates up to 1 Mbps•Thirty-two mailboxes, each with the following properties:– Configurable as receive or transmit– Configurable with standard or extended identifier– Has a programmable acceptance filter mask– Supports data and remote frame– Supports 0 to 8 bytes of data– Uses a 32-bit time stamp on received and transmitted message– Protects against reception of new message– Allows dynamically programmable priority of transmit message– Employs a programmable interrupt scheme with two interrupt levels– Employs a programmable interrupt on transmission or reception time-out•Low–power mode•Programmable wake–up on bus activity•Automatic reply to a remote request message•Automatic retransmission of a frame in case of loss of arbitration or error•32-bit time-stamp counter synchronized by a specific message (communication in conjunction withmailbox 16)•Self–test mode– Operates in a loopback mode receiving its own message. A “dummy” acknowledge is provided,thereby eliminating the need for another node to provide the acknowledge bit.

10 Architecture SPRU074F – May 2002 – Revised January 2009Submit Documentation Feedback

Table of contents

Other Texas Instruments Controllers manuals

Texas Instruments

Texas Instruments EDMA3 User manual

Texas Instruments

Texas Instruments TMS320C6455 User manual

Texas Instruments

Texas Instruments TPS53681EVM-002 User manual

Texas Instruments

Texas Instruments TMS320C6000 DSP User manual

Texas Instruments

Texas Instruments TMS320x2833x User manual

Texas Instruments

Texas Instruments TMS320 2833 Series User manual

Texas Instruments

Texas Instruments TMS320C6452 DSP User manual

Texas Instruments

Texas Instruments TPS23755 User manual

Texas Instruments

Texas Instruments UCC14240EVM-052 User manual

Texas Instruments

Texas Instruments UCC28600 User manual

Texas Instruments

Texas Instruments TMDSHVMTRPFCKIT User manual

Texas Instruments

Texas Instruments bq24725A User manual

Texas Instruments

Texas Instruments TMS320C6000 DSP User manual

Texas Instruments

Texas Instruments TPS40100 User manual

Texas Instruments

Texas Instruments bq78350-R1 Use and care manual

Texas Instruments

Texas Instruments TMS320x2833 series User manual

Texas Instruments

Texas Instruments TPS59640EVM-751 User manual

Texas Instruments

Texas Instruments TMS320C674X User manual

Texas Instruments

Texas Instruments LM5020 User manual

Texas Instruments

Texas Instruments DLPC3430 Manual

Texas Instruments

Texas Instruments LM3429 User manual

Texas Instruments

Texas Instruments TCAN4550-Q1 User manual

Texas Instruments

Texas Instruments TUSB3200EVM2 User manual

Texas Instruments

Texas Instruments TPS65987D User manual

Popular Controllers manuals by other brands

Digiplex

Digiplex DGP-848 Programming guide

YASKAWA

YASKAWA SGM series user manual

Sinope

Sinope Calypso RM3500ZB installation guide

Isimet

Isimet DLA Series Style 2 Installation, Operations, Start-up and Maintenance Instructions

LSIS

LSIS sv-ip5a user manual

Rockwell Automation

Rockwell Automation 1769-L31 installation instructions

Airflow

Airflow Uno hab Installation and operating instructions

ABB

ABB ACS580-01 drives Hardware manual

Panasonic

Panasonic GM1 Series Reference manual

Emerson

Emerson SW93 owner's manual

AutoAqua

AutoAqua Smart ATO micro SATO-120P manual

Panasonic

Panasonic FP? Positioning Unit RTEX Technical manual

Samson

Samson Type 5824 Mounting and operating instructions

Alpha IP

Alpha IP MIOB 21001 manual

Siemens

Siemens OpenAir GMA 1 Series Mounting instructions

Surecom

Surecom SR-629 user manual

Fishman

Fishman TriplePlay installation guide

Regulus

Regulus SRS1 T Installation and operation manual