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FUJITSU MB91460 SERIES FR60 User Manual

Page 673

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657

Chapter 32 USART (LIN / FIFO)

7.USART Operation

Table 7-3 Selection of the master-slave communication function

Communication Procedure

When the master CPU transmits address data, communication starts. The A/D bit in the address data is set to
1, and the communication destination slave CPU is selected. Each slave CPU checks the address data using
a program. When the address data indicates the address assigned to a slave CPU, the slave CPU
communicates with the master CPU (ordinary data). Figure

7-12

shows a flowchart of master-slave

communication (multiprocessor mode)

Operation mode

Data

Parity

Synchro-

nization

method

Stop bit

Bit

direction

Master

CPU

Slave CPU

Address
transmis-
sion and
reception

Mode 1
(send AD-
bit)

Mode 1
(receive
AD-bit)

AD="1" +
7- or 8-bit
address

None

Asyn-
chronous

1 or 2

bits

LSB

or

MSB

first

Data trans-
mission
and recep-
tion

AD="0" +
7- or 8-bit
data