Initialization; Figure 14.25 Receive Data Sampling Timing In Smart Card Mode (Using Clock Of 372 Times The Bit Rate) - Renesas H8S/2368 Series Hardware Manual

Internal
basic clock
Receive data
(RxD)
Synchronization
sampling timing
Data sampling
timing
Figure 14.25 Receive Data Sampling Timing in Smart Card Mode
14.7.5

Initialization

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. Set the PE bit to 1.
4. Set the SMIF, SDIR, and SINV bits in SCMR.
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.
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.
If the CKE0 bit is set to 1, the clock is output from the SCK pin.
7. Wait at least one bit interval, then set the TIE, RIE, TE, and RE bits in SCR. Do not set the TE
bit and RE bit at the same time, except for self-diagnosis.
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.
Rev. 2.00, 05/03, page 570 of 820
372 clocks
186 clocks
0 185 371
Start bit
(Using Clock of 372 Times the Bit Rate)
185
0
D0
371 0
D1