HD64F3039F18 Datasheet, PDF (430/710 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer H8 Family / H8/300H Series

Section 12 Smart Card Interface
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.
Rev.3.00 Mar. 26, 2007 Page 406 of 682
REJ09B0353-0300