r4f2426 Renesas Electronics Corporation., r4f2426 Datasheet - Page 928

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

Section 15 Serial Communication Interface (SCI, IrDA)
15.7.5
Before transmitting and receiving data, initialize the SCI as described below. Initialization is also
necessary when switching from transmit mode to receive mode, or vice versa.
1. Clear the TE and RE bits in SCR to 0.
2. Clear the error flags ERS, PER, and ORER in SSR to 0.
3. Set the GM, BLK, O/E, BCP1, BCP0, CKS1, and CKS0 bits in SMR, and the BCP2 bit in
4. Set the SMIF, SDIR, and SINV bits in SCMR.
5. Set the value corresponding to the bit rate in BRR.
6. Set the CKE0 and CKE1 bits in SCR. Clear the TIE, RIE, TE, RE, MPIE, and TEIE bits to 0.
7. Wait at least one bit interval, then set the TIE, RIE, TE, and RE bits in SCR. Do not set the TE
To switch from receive mode to transmit mode, after checking that the SCI has finished reception,
initialize the SCI, and clear RE to 0 and set TE to 1. Whether SCI has finished reception can be
checked with the RDRF, PER, or ORER flag. To switch from transmit mode to receive mode,
after checking that the SCI has finished transmission, initialize the SCI, and clear TE to 0 and set
RE to 1. Whether SCI has finished transmission can be checked with the TEND flag.
15.7.6
As data transmission in Smart Card interface mode involves error signal sampling and
retransmission processing, the operations are different from those in normal serial communication
interface mode (except for block transfer mode). Figure 15.26 illustrates the retransfer operation
when the SCI is in transmit mode.
1. If an error signal is sampled from the receiving end after transmission of one frame is
2. The TEND bit in SSR is not set for a frame for which an error signal is received. Data is
3. If an error signal is not sent back from the receiving end, the ERS bit in SSR is not set.
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SCMR. Set the PE bit to 1.
When the SMIF bit is set to 1, the TxD and RxD pins are both switched from ports to SCI pins,
and are placed in the high-impedance state.
If the CKE0 bit is set to 1, the clock is output from the SCK pin.
bit and RE bit at the same time, except for self-diagnosis.
completed, the ERS bit in SSR is set to 1. If the RIE bit in SCR is set at this time, an ERI
interrupt request is generated. The ERS bit in SSR should be cleared to 0 before the next parity
bit is sampled.
retransferred from TDR to TSR, and retransmitted automatically.
Initialization
Data Transmission (Except for Block Transfer Mode)