r4f2426 Renesas Electronics Corporation., r4f2426 Datasheet - Page 945

• Manufacturer Part Number: r4f2426
• Description: 16-bit Single-chip Microcomputer H8s Family / H8s/2400 Series
• Manufacturer: Renesas Electronics Corporation.

15.10.7 Operation in Case of Mode Transition
• Transmission
• Reception
Operation should be stopped (by clearing TE, TIE, and TEIE to 0) before making a module
stop mode or software standby mode transition. TSR, TDR, and SSR are reset. The output pin
states in module stop mode or software standby mode depend on the port settings, and become
high-level output after the relevant mode is cleared. If a transition is made during transmission,
the data being transmitted will be undefined.
When transmitting without changing the transmit mode after the relevant mode is cleared,
transmission can be started by setting TE to 1 again, and performing the following sequence:
SSR read → TDR write → TDRE clearance. To transmit with a different transmit mode after
clearing the relevant mode, the procedure must be started again from initialization.
Figure 15.36 shows a sample flowchart for mode transition during transmission. Port pin states
during mode transition are shown in figures 15.37 and 15.38.
Operation should also be stopped (by clearing TE, TIE, and TEIE to 0) before making a
transition from transmission by DTC transfer to module stop mode or software standby mode
transition. To perform transmission with the DTC after the relevant mode is cleared, setting TE
and TIE to 1 will set the TXI flag and start DTC transmission.
Receive operation should be stopped (by clearing RE to 0) before making a module stop mode
or software standby mode transition. RSR, RDR, and SSR are reset. If a transition is made
during reception, the data being received will be invalid.
To continue receiving without changing the reception mode after the relevant mode is cleared,
set RE to 1 before starting reception. To receive with a different receive mode, the procedure
must be started again from initialization.
Figure 15.39 shows a sample flowchart for mode transition during reception.
Section 15 Serial Communication Interface (SCI, IrDA)
Rev. 1.00 Sep. 19, 2008 Page 917 of 1270
REJ09B0466-0100