Figure 10.12 Example Of Operation When Transmitting In Asynchronous Mode (8-Bit Data, Parity, 1 Stop Bit) - Renesas H8/3847R Series Hardware Manual

8-bit single-chip microcomputer super low power

Table of Contents

Section 10 Serial Communication Interface

SCI3 operates as follows when transmitting data.

SCI3 monitors bit TDRE in SSR, and when it is cleared to 0, recognizes that data has been written

to TDR and transfers data from TDR to TSR. It then sets bit TDRE to 1 and starts transmitting. If

bit TIE in SCR3 is set to 1 at this time, a TXI request is made.

Serial data is transmitted from the TXD3x pin using the relevant data transfer format in table

10.14. When the stop bit is sent, SCI3 checks bit TDRE. If bit TDRE is cleared to 0, SCI3

transfers data from TDR to TSR, and when the stop bit has been sent, starts transmission of the

next frame. If bit TDRE is set to 1, bit TEND in SSR bit is set to 1the mark state, in which 1s are

transmitted, is established after the stop bit has been sent. If bit TEIE in SCR3 is set to 1 at this

time, a TEI request is made.

Figure 10.12 shows an example of the operation when transmitting in asynchronous mode.

Figure 10.12 Example of Operation when Transmitting in Asynchronous Mode

Rev. 6.00 Aug 04, 2006 page 384 of 680

REJ09B0145-0600

cleared to 0

Data written

(8-bit data, parity, 1 stop bit)