HD6412320 RENESAS [Renesas Technology Corp], HD6412320 Datasheet - Page 692

• Manufacturer Part Number: HD6412320
• Description: Renesas 16-Bit Single-Chip Microcomputer H8S Family H8S-2300 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

Section 14 Serial Communication Interface (SCI)
Operation in Case of Mode Transition
• Transmission
• Reception
Rev.6.00 Sep. 27, 2007 Page 662 of 1268
REJ09B0220-0600
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
becomes 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 14.23 shows a sample flowchart
for mode transition during transmission. Port pin states are shown in figures 14.24 and 14.25.
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
without stopping operation, 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 14.26 shows a sample flowchart for mode transition during reception.