Mazda CX-9 2007 Service Highlights page 597

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
CONNECTOR
INPUT
INTERFACE
CONVENTIONAL MODULE
Twisted Pair
• The multichannel use 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
if difficult for noise interference to be received.
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
OUTPUT
INTERFACE
CPU
Function
CAN HARNESS
(TWISTED PAIR) CONVENTIONAL
CONNECTOR
MULTIPLEX
INPUT
CPU
INTERFACE
BLOCK
COMPUTATION
PROCESSING BLOCK
CAN SYSTEM-RELATED MODULE
CA N_ H
id094000101000
WIRING HARNESS
OUTPUT
INTERFACE
acxuun00000506
CA N_L
acxuun00000507
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