H8SSLASH2218 datasheet(476/750 Pages) RENESAS

476 / 750 page

Section 12 Serial Communication Interface

Rev.6.00 Jun. 03, 2008 Page 428 of 698

REJ09B0074-0600

12.7.2

Data Format (Except for Block Transfer Mode)

Figure 12.25 shows the transfer data format in Smart Card interface mode.

• One frame consists of 8-bit data plus a parity bit in asynchronous mode.

• In transmission, a guard time of at least 2 etu (Elementary time unit: the time for transfer of

one bit) is left between the end of the parity bit and the start of the next frame.

• If a parity error is detected during reception, a low error signal level is output for one etu

period, 10.5 etu after the start bit.

• If an error signal is sampled during transmission, the same data is retransmitted automatically

after a delay of 2 etu or longer.

When there is no parity error

Transmitting station output

When a parity error occurs

Transmitting station output

Receiving station

output

Start bit

Data bits

Parity bit

Error signal

Legend:

D0 to D7:

Dp:

DE:

Figure 12.25 Normal Smart Card Interface Data Format

Data transfer with other types of IC cards (direct convention and inverse convention) are

performed as described in the following.

(Z)

State

Figure 12.26 Direct Convention (SDIR = SINV = O/

E = 0)

With the direction convention type IC and the above sample start character, 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

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