The eCAN controller provides the CPU with full functionality of the CAN protocol. The CAN controller minimizes
the CPU’s load in communication overhead and enhances the CAN standard by providing additional features.
The architecture of eCAN module, shown in
, is composed of a CAN protocol kernel (CPK) and a
message controller.
CAN Bus
CAN controller
Message Controller
CAN Protocol Kernel (CPK)
CAN Transceiver
RX
TX
CPU
Receive Buffer
A
Transmit Buffer
A
A.
The receive and transmit buffers are transparent to the user and are not accessible by user code.
Figure 16-3. Architecture of the eCAN Module
One function of the CPK is to decode all messages received on the CAN bus and to transfer these messages
into a receive buffer. Another function is to transmit messages on the CAN bus according to the CAN protocol.
The message controller of a CAN controller is responsible for determining if any message received by the
CPK must be preserved for the CPU use (that is, copied into the mailbox RAM) or be discarded. At the
initialization phase, the CPU specifies to the message controller all message identifiers used by the application.
The message controller is also responsible for sending the next message to transmit to the CPK according to the
message’s priority.
Controller Area Network (CAN)
SPRUH18I – JANUARY 2011 – REVISED JUNE 2022
TMS320x2806x Microcontrollers
1003
Copyright © 2022 Texas Instruments Incorporated
Содержание TMS320 2806 Series
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