DCAN
Message
Module Interface
CAN Core
Message Handler
RAM
Interface
CTRL
OCP Interface
CAN_TX
Message
RAM
64
Message
(8, 16 or 32 bit)
INT req.
DMA req.
CAN_CLK
CAN_RX
Registers and
Message Object Access
Objects
L3_SLOW_GCLK_(OCP)
DEV_OSC (Func)
Functional Description
23.3 Functional Description
The DCAN module performs CAN protocol communication according to ISO 11898-1. The bit rate can be
programmed to values up to 1 MBit/s. Additional transceiver hardware is required for the connection to the
physical layer (CAN bus).
For communication on a CAN network, individual message objects can be configured. The message
objects and identifier masks are stored in the message RAM.
All functions concerning the handling of messages are implemented in the message handler. Those
functions are acceptance filtering, the transfer of messages between the CAN core and the message
RAM, and the handling of transmission requests, as well as the generation of interrupts or DMA requests.
The register set of the DCAN module can be accessed directly by the CPU via the module interface.
These registers are used to control and configure the CAN core and the message handler, and to access
the message RAM.
shows the DCAN block diagram and its features are described below.
Figure 23-2. DCAN Block Diagram
23.3.1 CAN Core
The CAN core consists of the CAN protocol controller and the Rx/Tx shift register. It handles all ISO
11898-1 protocol functions.
3885
SPRUH73H – October 2011 – Revised April 2013
Controller Area Network (CAN)
Copyright © 2011–2013, Texas Instruments Incorporated