Renesas H8S/2318 series, Hardware Manual

Page: 534 / 1121

Rev. 5.00, 12/03, page 504 of 1088
13.3.6 Data Transfer Operations
Initialization: Before transmitting or 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 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 CKE1 and CKE0 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.