h8s-2649 Renesas Electronics Corporation., h8s-2649 Datasheet - Page 442

• Manufacturer Part Number: h8s-2649
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2600 Series
• Manufacturer: Renesas Electronics Corporation.

Section 13 Serial Communication Interface (SCI)
13.7.5
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, BCP0, BCP1, CKS0, and CKS1 bits in SMR. Set the PE bit to 1.
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 set RE to 0 and TE to 1. Whether SCI has finished reception or not can be
checked with the RDRF, PER, or ORER flags. To switch from transmit mode to receive mode,
Rev. 2.00 Dec. 05, 2005 Page 404 of 724
REJ09B0200-0200
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.
Internal
basic clock
Receive data
(RxD)
Synchronization
sampling timing
Data sampling
timing
Initialization
Figure 13.25 Receive Data Sampling Timing in Smart Card Mode
186 clocks
0
(Using Clock of 372 Times the Transfer Rate)
185
372 clocks
Start bit
371
0
D0
185
371 0
D1