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1 overview of uart – FUJITSU MB91F109 FR30 User Manual

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CHAPTER 10 UART

10.1 Overview of UART

The UART is a serial I/O port used to implement asynchronous (start-stop)
communication or CLK synchronous communication.
The MB91F109 contains three UART channels.

UART Characteristics

Full duplex double buffer

Support of both asynchronous (start-stop) and CLK synchronous communication

Support of multiprocessor mode

Fully programmable baud rate

Any baud rate can be set using the built-in timer (See Section 9.3, "U-TIMER Operation").

Support for setting any baud rate using external clocks

Error detection function (parity errors, framing errors, and overrun)

NRZ code for transfer signal

Support for starting DMA transfer by an interrupt

UART Registers

Figure 10.1-1 shows the UART registers.

Figure 10.1-1 UART Registers

15

8

7

0

SCR

SMR

(R/W)

SSR

SIDR(R)/SODR(W)

(R/W)

8 bit

8 bit

7

6

5

4

3

2

1

0

D7

D6

D5

D4

D3

D2

D1

D0

(SIDR / SODR)

7

6

5

4

3

2

1

0

PE

ORE

FRE

RDRF TDRE

RIE

TIE

(SSR)

7

6

5

4

3

2

1

0

MD1

MD0

CS0

SCKE

SOE

(SMR)

7

6

5

4

3

2

1

0

PEN

P

SBL

CL

A/D

REC

RXE

TXE

(SCR)

Serial input data register/serial output

data register (SIDR/SODR)

Serial status register

Serial mode register

Serial control register