beautypg.com

Chapter 32 usart (lin / fifo), Overview – FUJITSU MB91460 SERIES FR60 User Manual

Page 629

background image

613

Chapter 32 USART (LIN / FIFO)

1.Overview

Chapter 32 USART (LIN / FIFO)

1. Overview

This chapter explains the function and operation of the USART. The USART with LIN (Local Interconnect
Network) - Function is a general-purpose serial data communication interface for performing synchronous or
asynchronous communication with external devices. 16 bytes transmission and reception FIFOs are available
for selected channels.

The USART provides bidirectional communication function (normal mode), master-slave communication
function (multiprocessor mode in master/slave systems), and special features for LIN-bus systems (working
both as master or as slave device).

(Note)

This chapter only lists the registers and addresses of USART04. Please refer to the IO-Map for the
addresses of the other USARTs.

USART Functions

USART is a general-purpose serial data communication interface for transmitting serial data to and receiving
data from another CPU or peripheral devices. It has the functions listed in
table

1-1

.

Table 1-1 USART functions

Item

Function

Data buffer

Full-duplex

Serial Input

5 times oversampling in asynchronous mode

Transfer mode

- Clock synchronous (start-stop synchronization and

start-stop-bit-option)

- Clock asynchronous (using start-, stop-bits)

Baud rate

- A dedicated baud rate generator is provided, which

consists of a 15-bit-reload counter

- An external clock can be input and also be adjusted

by the reload counter

Data length

- 7 bits (not in synchronous or LIN mode)
- 8 bits

Signal mode

Non-return to zero (NRZ) and return to zero (RZ)

Start bit timing

Clock synchronization to the falling edge of the start bit
in asynchronous mode

Reception error
detection

- Framing error
- Overrun error
- Parity error

Interrupt request

- Reception interrupt (reception complete, reception

error detect, Bus-Idle, LIN-Synch-break detect)

- Transmission interrupt (transmission complete)