Operation In Asynchronous Mode - Renesas F-ZTAT H8 Series Hardware Manual

TDR (next transmit data)
TSR (transmitting)
TXD
pin
TDRE = 0
TDR
TSR (transmitting)
TXD
pin
10.3.4

Operation in Asynchronous Mode

In asynchronous communication mode, a start bit indicating the start of communication and a stop
bit indicating the end of communication are added to each character that is sent. In this way
synchronization is achieved for each character as a self-contained unit.
SCI3 consists of independent transmit and receive modules, giving it the capability of full duplex
communication. Both the transmit and receive modules have a double-buffer configuration,
allowing data to be read or written during communication operations so that data can be
transmitted and received continuously.
Figure 10.5 TDRE Setting and TXI Interrupt
TEND = 0
Figure 10.6 TEND Setting and TEI Interrupt
10. Serial Communication Interface
TDR
↓
TSR (transmission complete,
next data transferred)
TXD
pin
TDRE
(TXI requested if TIE = 1)
TDR
TSR (transmission end)
TXD
pin
(TEI requested if TEIE = 1)
Rev.3.00 Jul. 19, 2007 page 283 of 532
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