Data Format (Except In Block Transfer Mode) - Renesas H8S/2100 Series Hardware Manual

14.7.2

Data Format (Except in Block Transfer Mode)

Figure 14.22 shows the data transfer formats in smart card interface mode.
• One frame contains 8-bit data and a parity bit in asynchronous mode.
• During transmission, at least 2 etu (elementary time unit: time required for transferring one bit)
is secured as a guard time after the end of the parity bit before the start of the next frame.
• If a parity error is detected during reception, a low error signal is output for 1 etu after 10.5 etu
has passed from the start bit.
• If an error signal is sampled during transmission, the same data is automatically re-transmitted
after two or more etu.
In normal transmission/reception
When a parity error is generated
[Legend]
Ds:
D0 to D7 :
Dp:
DE:
Figure 14.22 Data Formats in Normal Smart Card Interface Mode
For communication with the IC cards of the direct convention and inverse convention types,
follow the procedure below.
(Z)
Figure 14.23 Direct Convention (SDIR = SINV = O/E = 0)
Ds D0 D1 D2 D3
Output from the transmitting station
Ds D0 D1 D2 D3
Output from the transmitting station
Start bit
Data bits
Parity bit
Error signal
A Z Z A Z
Ds D0 D1 D2 D3
Section 14 Serial Communication Interface (SCI)
D4 D5 D6 D7 Dp
D4 D5 D6 D7 Dp
Z Z A A Z
D4 D5 D6 D7 Dp
Rev. 1.00 May 09, 2008 Page 409 of 954
DE
Output from
the receiving station
(Z) state
REJ09B0462-0100