H8S2426 Datasheet, PDF (925/1302 Pages) Renesas Technology Corp – 16-Bit Single-Chip Microcomputer H8S Family / H8S/2400 Series

Section 15 Serial Communication Interface (SCI, IrDA)
As in the above sample start character, with the direct convention type, the logic 1 level
corresponds to state Z and the logic 0 level to state A, and transfer is performed in LSB-first order.
The start character data above is H'3B. For the direct convention type, clear the SDIR and SINV
bits in SCMR to 0. According to the Smart Card regulations, clear the O/E bit in SMR to 0 to
select even parity mode.
(Z) A Z Z A A A A A A Z
Ds D7 D6 D5 D4 D3 D2 D1 D0 Dp
(Z) State
Figure 15.24 Inverse Convention (SDIR = SINV = O/E = 1)
With the inverse convention type, the logic 1 level corresponds to state A and the logic 0 level to
state Z, and transfer is performed in MSB-first order. The start character data above is H'3F. For
the inverse convention type, set the SDIR and SINV bits in SCMR to 1. According to the Smart
Card regulations, even parity mode is the logic 0 level of the parity bit, and corresponds to state Z.
In this LSI, the SINV bit inverts only data bits D7 to D0. Therefore, set the O/E bit in SMR to 1 to
invert the parity bit for both transmission and reception.
15.7.3 Block Transfer Mode
Operation in block transfer mode is the same as that in normal Smart Card interface, except for the
following points.
• In reception, though the parity check is performed, no error signal is output even if an error is
detected. However, the PER bit in SSR is set to 1 and must be cleared before receiving the
parity bit of the next frame.
• In transmission, a guard time of at least 1 etu is left between the end of the parity bit and the
start of the next frame.
• In transmission, because retransmission is not performed, the TEND flag is set to 1, 11.5 etu
after transmission start.
• As with the normal Smart Card interface, the ERS flag indicates the error signal status, but
since error signal transfer is not performed, this flag is always cleared to 0.
Rev. 1.00 Sep. 19, 2008 Page 897 of 1270
REJ09B0466-0100