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Serial Data Transmission: As data transmission in smart card mode involves error signal
sampling and retransmission processing, the processing procedure is different from that for the
normal SCI. Figure 12-4 shows an example of the transmission processing flow, and figure 12-5
shows the relation between a transmit operation and the internal registers.
[1] Perform Smart Card interface mode initialization as described above in Initialization.
[2] Check that the ERS error flag in SSR is cleared to 0.
[3] Repeat steps [2] and [3] until it can be confirmed that the TEND flag in SSR is set to 1.
[4] Write the transmit data to TDR, clear the TDRE flag to 0, and perform the transmit operation.
The TEND flag is cleared to 0.
[5] When transmitting data continuously, go back to step [2].
[6] To end transmission, clear the TE bit to 0.
With the above processing, interrupt servicing is possible.
If transmission ends and the TEND flag is set to 1 while the TIE bit is set to 1 and interrupt
requests are enabled, a transmit data empty interrupt (TXI) request will be generated. If an error
occurs in transmission and the ERS flag is set to 1 while the RIE bit is set to 1 and interrupt
requests are enabled, a transfer error interrupt (ERI) request will be generated.
For details, see the following Interrupt Operations.
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