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FUJITSU MB91460 SERIES FR60 User Manual

Page 630

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Chapter 32 USART (LIN / FIFO)

1.Overview

USART operation modes

The USART operates in four different modes, which are determined by the MD0- and the MD1-bit of the Serial
mode register (SMR04). Mode 0 and 2 are used for bidirectional serial communication, mode 1 for master/
slave communication and mode 3 for LIN master/slave communication.

* means the data bit transfer format: LSB or MSB first.

** "+1" means the indicator bit of the address/data selection in the multiprocessor mode, instead of parity.

Mode 1 operation is supported both for master or slave operation of USART in a master-slave connection
system. In Mode 3 the USART function is locked to 8N1-Format, LSB first.

If the mode is changed, USART cuts off all possible transmission or reception and then awaits new action.

The MD1 and MD0 bits of the Serial Mode Register (SMR04) determine the operation mode of USART04 as
shown in the following table:

Master-slave communication
function
(multiprocessor mode)

One-to-n communication (one master to n slaves)
(This function is supported both for master and slave
system).

Synchronous mode

Function as Master- or Slave-USART

Transceiving pins

Direct access possible

LIN bus options

- Operation as master device
- Operation as slave device
- Generation of LIN-Sync-break
- Detection of LIN-Sync-break
- Detection of start/stop edges in LIN-Sync-field

connected to ICU 0 and 2

Synchronous serial clock

The synchronous serial clock can be output
continuously on the SCK pin for synchronous
communication with start & stop bits

Clock delay option

Special synchronous Clock Mode for delaying clock
(useful for SPI-compliance)

16 word deep FIFO

FIFO can be activated with receive progammable
trigger level

Table 1-2 USART operation modes

Operation

mode

Data length

Synchroniza-

tion of mode

Length

of

stop bit

data bit

directio

n*

parity

disabled

parity

enabled

0

normal mode

7 or 8

asynchronous

1 or 2

L/M

1

multiprocessor

7 or 8 + 1**

-

asynchronous

1 or 2

L/M

2

normal mode

8

synchronous

0, 1 or 2

L/M

3

LIN mode

8

-

asynchronous

1

L

Table 1-1 USART functions (continued)