Datasheet

Section 13 Serial Communication Interface (SCI)
Rev. 3.00 Sep. 28, 2009 Page 313 of 710
REJ09B0384-0300
13.9.7 SCI Operations during Mode Transitions
Transmission: Before making the transition to module stop or software standby, stop all transmit
operations (TE = TIE = TEIE = 0). TSR, TDR, and SSR are reset. The states of the output pins
during each mode depend on the port settings, and the pins output a high-level signal after mode
cancellation. If the transition is made during data transmission, the data being transmitted will be
undefined.
To transmit data in the same transmission mode after mode cancellation, set TE to 1, read SSR,
write to TDR, clear TDRE in this order, and then start transmission. To transmit data in a different
transmission mode, initialize the SCI first.
Figure 13.34 shows a sample flowchart for mode transition during transmission. Figures 13.35 and
13.36 show the pin states during transmission.
Before making the transition from the transmission mode using DTC transfer to module stop or
software standby, stop all transmit operations (TE = TIE = TEIE = 0). Setting TE and TIE to 1
after mode cancellation generates a TXI interrupt request to start transmission using the DTC.