SH7727 Datasheet, PDF (627/1109 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH RISC engine Family/SH7700 Series

Section 18 Smart Card Interface
18.3.6 Data Transmission and Reception
Initialization: Initialize the SCI0 using the following procedure before sending or receiving data.
Initialization is also required for switching from transmit mode to receive mode or from receive
mode to transmit mode. Figure 18.5 shows a flowchart of the initialization process (example).
1. Clear TE and RE in the serial control register (SCSCR) to 0.
2. Clear error flags FER/ERS, PER, and ORER to 0 in the serial status register (SCSSR).
3. Set the C/A bit, parity bit (O/E bit), and baud rate generator select bits (CKS1 and CKS0 bits)
in the serial mode register (SCSMR). At this time also clear the CHR and MP bits to 0 and set
the STOP and PE bits to 1.
4. Set the SMIF, SDIR, and SINV bits in the smart card mode register (SCSCMR). When the
SMIF bit is set to 1, the TxD and RxD pins both switch from ports to SCI0 pins and become
high impedance.
5. Set the value corresponding to the bit rate in the bit rate register (SCBRR).
6. Set the clock source select bits (CKE1 and CKE0 bits) in the serial control register (SCSCR).
Clear the TIE, RIE, TE, RE, MPIE, and TEIE bits to 0. When the CKE0 bit is set to 1, a clock
is output from the SCK pin.
7. After waiting at least 1 bit, set the TIE, RIE, TE, and RE bits in SCSCR. Do not set the TE and
RE bits simultaneously unless performing auto-diagnosis.
Rev. 5.00 Dec 12, 2005 page 555 of 1034
REJ09B0254-0500