M16C Datasheet, PDF (163/262 Pages) Mitsubishi Electric Semiconductor – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

Preliminary Specifications REV.B
Mitsubishi microcomputers
Specifications in this manual are tentative and subject to change.
M16C / 6N Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
CAN Module
CAN Module 0/1
The CAN module provides the CAN (Controller Area Network) serial-bus data communication interface. This
asynchronous communication protocol is used in distributed systems, such as automotive and industrial
control systems and where high-speed processing and data exchange are required with a very high level of
security. This module supports data transfer rates up to 1 Mbps.
According to the BOSCH 2.0B CAN protocol specification, the CAN module can handle and process both
the standard and extended identifier message formats. For more details, refer to the BOSCH CAN Specifi-
cation 2.0B, hereinafter referred to as CAN specification.
Data Bus
CAN Configuration
Register
CAN Control
Register
CAN Message
Control
Register 0 -15
CAN Global Mask
Register
CAN Local Mask A
Register
CAN Local Mask B
Register
CAN ExtID
Register
CTX
Protocol
Controller
CRX
Wake Up
Logic
CAN REC
Register
CAN TEC
Register
CAN Status
Register
Acceptance Filter
Mailbox 0 - 15
16 Bit Timer
CAN Time Stamp
Register
CAN Slot Status
Register
CAN Int Control
Register
Data Bus
Message
Mailbox
Slot 0 - 15
Message ID
DLC
Message Data
Time Stamp
Interrupt
Control
Logic
RecSuc Int
TrmSuc Int
CAN Error Int
CAN Wake-Up Int
Figure 18-1. Block diagram of one CAN module
Figure 18-1 shows a block diagram of the M16C CAN module. The main functional blocks in this description are:
Protocol Controller:
Message Mailbox:
Acceptance Filter:
16 bit Timer:
This controller handles the bus arbitration and the CAN serial communication protocol
message transmission and reception services, i.e. bit stuffing, CRC, error status etc.
This memory block consists of several message slots which can be configured to act
either as a transmit- or receive message box. Each slot consists of a relevant identi-
fier, data length code, a data field (8 bytes) and a communication time stamp. This
message slot time stamp value corresponds to the instant of time (event) when the
Protocol Controller indicates a successful CAN message reception.
This block performs the comparison between the identifier of the received message
and the key identifier of all receive slots. For this acceptance filter, users can define
the content of special mask registers to filter a range of identifier for the correspond-
ing message slot.
This 16 bit timer is used for a time stamp function. The timer provides the counter
status which will be stored together with the received message in the message mail-
box.
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