SH7721 datasheet(1074/1524 Pages) RENESAS

1074 / 1524 page

Section 30

SIM Card Module (SIM)

Rev. 3.00 Jan. 18, 2008 Page 1012 of 1458

REJ09B0033-0300

30.4.5

Data Transmit/Receive Operation

(1)

Initialization

Prior to data transmission and reception, the following procedure should be used to initialize the

smart card interface. Initialization is also necessary when switching from transmit mode to receive

mode, and when switching from receive mode to transmit mode. An example of the initialization

process is shown in the flowchart of figure 30.4.

Step (1) to step (7) of figure 30.4 correspond to the following operation.

1. Clear the TE and RE bits in the serial control register (SCSCR) to 0.

2. Clear the error flags PER, ORER, ERS, and WAIT_ER in the serial status register (SCSSR) to

3. Set the parity bit (O/

E bit) in the serial mode register (SCSMR).

4. Set the LCB, PB, SMIF, SDIR, and SINV bits in the smart card mode register (SCSCMR).

5. Set the value corresponding to the bit rate to the bit rate register (SCBRR).

6. Set the clock source select bits (CKE1 and CKE0 bits) in the serial control register (SCSCR).

At this time, the TIE, RIE, TE, RE, TEIE, and WAIT_IE bits should be cleared to 0.

If the CKE0 bit is set to 1, a clock signal is output from the SIM_CLK pin.

7. After waiting at least 1 etu, set the TIE, RIE, TE, RE, TEIE, and WAIT_IE bits in SCSCR.

Except for self-check, the TE bit and RE bit should not be set simultaneously.

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