Mazda RX-8 2004 Service Highlights page 532

CAN SYSTEM DESCRIPTION
Mechanism of CAN System-Related Module
• A CAN system-related module is composed of an electrical circuit, CPU, and input/output interface.
• The size of the module has been reduced due to the elimination of the bulky, superfluous, input/output interface
in the conventional type of electrical module.
• The CPU (multiplex block) controls all signals exchanged on the CAN harness.
• Communication with non-multiplex parts is carried out by conventional input/output interface.
• The functions of each component are shown below.
Component
Electrical circuit
Computation processing block Control function has been expanded, and when transmission is necessary,
CPU
Multiplex block
Input/Output interface
INPUT
SIGNAL
INPUT
INTERFACE
CONVENTIONAL MODULE
Twisted Pair
• The multichannel uses two spirally twisted wires
called a twisted pair, and each wire, CAN_L and
CAN_H, has its own special function.
• Both bus lines are opposite phase voltage. This
allows for minimal noise being emitted and makes
it difficult for noise interference to be received.
09–40–2
CONTROL SYSTEM
Supplies power to CPU and vicinity, and to input/output interface.
transmitted data is stored in a multiplex block. If a multiplex block receives a
request to read stored data, transmitted data is read from the multiplex block.
Transmits data received from bus line to computation processing block. In
addition, sends transmitted data stored from computation processing block to
bus line.
Electrically converts information signals from switches to, be input to CPU,
and signals output from CPU for operating actuator or indicator lights.
OUTPUT
SIGNAL
CONNECTOR
OUTPUT
INTERFACE
CPU
Function
CAN HARNESS
(TWISTED PAIR)
CONNECTOR
MULTIPLEX
CPU
BLOCK
COMPUTATION
PROCESSING BLOCK
CAN SYSTEM-RELATED MODULE
CAN_H
CHU094055430S04
CONVENTIONAL
WIRING HARNESS
INPUT
OUTPUT
INTERFACE
INTERFACE
A6A8111T003
CAN_L
B6U0940S003