CAN Bus Controller with Message Filter (Mailbox concept)

Overview

CANmodule-IIIx is a full functional CAN controller module that supports the concept of mailboxes. It is compliant to the international CAN standard defined in ISO 11898-1.

It contains 32 receive buffers, each one with its own message filter, and 32 transmit buffers with prioritized arbitration scheme. For optimal support of Higher Layer Protocols (HLP) such as DeviceNet or SDC, the message filter covers the first two data bytes as well.

The design is written in technology independent HDL and can be mapped to ASIC and FPGA architectures and makes use of on-chip SRAM structures. An AMBA 3 Advanced Peripheral Bus (APB) interface enables smooth integration into ARM based SOC’s. This full synchronous bus interface can easily be connect to other system buses.

Key Features

Standard Compliant

Full CAN 2.0A/B compliant
Conforms to ISO 11898-1
Tested according to ISO 16845
Maximum baudrate of 1 Mbps with 8 MHz system clock

Receive Path

32 receive buffers
Each buffer has its own message filter
Message filter covers: ID, IDE, RTR, Data byte 1 and Data byte 2
Message buffers can be linked together to build a bigger message array
Automatic remote transmission request (RTR) response handler with optional generation of RTR interrupt

Transmit Path

32 Tx message holding registers with programmable priority arbitration
Message abort command
Single-shot transmission (no automatic retransmission upon error or arbitration loss)

System Bus Interface

AMBA 3 Advanced Peripheral Bus (APB) Interface
Optional: AMBA Advanced High-performance (AHB) Interface
Full synchronous zero wait-states interface
Status and configuration interface

Programmable Interrupt Controller

Local interrupt controller covering message and CAN error sources

Test and Debugging Support

Listen only mode
Internal loopback mode
External loopback mode
SRAM test mode
Error capture register

Provides option to either

o show current bit position within CAN message
o show bit position and type of last captured CAN error

SRAM Based Message Buffers

Optimized for low gate-count implementation
Single port, synchronous memory based
100% Synchronous Design

Benefits

CAN networks can be used as an embedded communication system for microcontrollers as well as an open communication system for intelligent devices. The CAN serial bus system, originally developed for use in automobiles, is increasingly being used in industrial field bus systems, the similarities are remarkable. In both cases some of the major requirements are:

low cost,
the ability to function in a difficult electrical environment,
a high degree of realtime capability and
ease of use.

Application Specific Message Filters

We provide application specific message filters. Whether you need a DMA controller interface, special filter capabilities or message FIFOs with priority encoding we are happy to provide you with a one-stop shopping solution.

Block Diagram

Deliverables

Verilog RTL Source Code
Verification Suite

Functional Testbench including CANbus transceiver model and additional CAN nodes

Synthesis Script
Data Sheet
User Guide
Hotline Support by means of phone, fax and e-mail

Technical Specifications

Foundry, Node

Technology independant

Maturity

Silicon proven in ASIC and FPGA Technologies

Availability

now

Request Info