HD6432351 datasheet(656/1025 Pages) RENESAS

656 / 1025 page

Section 14 Smart Card Interface

Rev. 3.00 Sep 15, 2006 page 622 of 988

REJ09B0330-0300

14.3.3

Data Format

Figure 14.3 shows the Smart Card interface data format. In reception in this mode, a parity check

is carried out on each frame, and if an error is detected an error signal is sent back to the

transmitting end, and retransmission of the data is requested. If an error signal is sampled during

transmission, the same data is retransmitted.

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

Figure 14.3 Smart Card Interface Data Format

The operation sequence is as follows.

[1] When the data line is not in use it is in the high-impedance state, and is fixed high with a pull-

up resistor.

[2] The transmitting station starts transfer of one frame of data. The data frame starts with a start

bit (Ds, low-level), followed by 8 data bits (D0 to D7) and a parity bit (Dp).

[3] With the Smart Card interface, the data line then returns to the high-impedance state. The data

line is pulled high with a pull-up resistor.

HD6432351 Datasheet(PDF) 656 Page - Renesas Technology Corp