TMPR3916 datasheet(196/225 Pages) TOSHIBA

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Chapter 10 Asynchronous Serial Interface (UART)

Preliminary

10-21

10.4 Flow Charts

In this paragraph some flow charts are presented, which should help the user to perform basic

operations on the UART.

In these examples an upper layer which involves a software protocol is used: the transmitter will send

as first data frame a “block length” which will be used by the receiver to determine the number of

incoming data frames. So if n data frames have to be transmitted, the actual length of the transmission

will be of n+1 since the protocol uses the first frame as a control frame.

The user may choose to implement or not such a protocol, the reason for using it here is to give an

easy example on how to operate the UART.

It is not recommended to use the Timeout error in the receiver to determine the end of a transmission:

if the FIFO is empty the error will not occur. This bit is not suitable for flow control.

10.4.1

Transmitter programming

Figure 10.4.1 shows a basic example of transmission operation. The hardware RTS/CTS flow control

is used, the other parameters refer to:

•

8 bit data length

•

1 stop bit

•

even parity

•

MSB first

•

software operates in polling mode on the TX FIFO

TMPR3916 Datasheet(PDF) 196 Page - Toshiba Semiconductor