HD6417750RF240V Datasheet, PDF (413/606 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer H8S Family/H8S/2600 Series

Section 14 Serial Communication Interface (SCI)
RDRF flag is not. Consequently, the DTC is not activated, instead, an ERI interrupt request is sent
to the CPU. Therefore, the error flag should be cleared.
14.9 Usage Notes
14.9.1 Module Stop Mode Setting
SCI operation can be disabled or enabled using the module stop control register. The initial setting
is for SCI operation to be halted. Register access is enabled by clearing module stop mode. For
details, refer to section 20, Power-Down Modes.
14.9.2 Break Detection and Processing
When framing error detection is performed, a break can be detected by reading the RxD pin value
directly. In a break, the input from the RxD pin becomes all 0s, setting the FER flag, and possibly
the PER flag. Note that as the SCI continues the receive operation after receiving a break, even if
the FER flag is cleared to 0, it will be set to 1 again.
14.9.3 Mark State and Break Detection
When TE is 0, the TxD pin is used as an I/O port whose direction (input or output) and level are
determined by DR and DDR. This can be used to set the TxD pin to mark state (high level) or send
a break during serial data transmission. To maintain the communication line at mark state until TE
is set to 1, set both PCR and PDR to 1. As TE is cleared to 0 at this point, the TxD pin becomes an
I/O port, and 1 is output from the TxD pin. To send a break during serial transmission, first set
PCR to 1 and PDR to 0, and then clear TE to 0. When TE is cleared to 0, the transmitter is
initialized regardless of the current transmission state, the TxD pin becomes an I/O port, and 0 is
output from the TxD pin.
14.9.4 Receive Error Flags and Transmit Operations (Clocked Synchronous Mode Only)
Transmission cannot be started when a receive error flag (ORER, PER, or FER) is set to 1, even if
the TDRE flag is cleared to 0. Be sure to clear the receive error flags to 0 before starting
transmission. Note also that receive error flags cannot be cleared to 0 even if the RE bit is cleared
to 0.
Rev. 7.00 Sep. 11, 2009 Page 377 of 566
REJ09B0211-0700