HD64F2636F20 Datasheet, PDF (576/1512 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer H8S Family/H8S/2600 Series

Section 14 Smart Card Interface
H8S/2639, H8S/2638, H8S/2636,
H8S/2630, H8S/2635 Group
14.3.3 Data Format
Normal Transfer Mode: Figure 14-3 shows the normal 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
Ds D0 D1 D2 D3 D4 D5 D6 D7 Dp
Transmitting station output
When a parity error occurs
Ds D0 D1 D2 D3 D4 D5 D6 D7 Dp
DE
Legend:
Ds:
Start bit
D0 to D7: Data bits
Dp:
Parity bit
DE:
Error signal
Transmitting station output
Receiving station
output
Figure 14-3 Normal 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.
Page 526 of 1458
REJ09B0103-0800 Rev. 8.00
May 28, 2010