SH7706 Datasheet, PDF (477/749 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH™ RISC engine Family/SH7700 Series

Section 15 Smart Card Interface
The operating sequence is:
1. The data line is high impedance when not in use and is fixed high with a pull-up resistor.
2. The transmitting side starts one frame of data transmission. The data frame starts with a start
bit (Ds, low level). The start bit is followed by eight data bits (D0 to D7) and a parity bit (Dp).
3. On the smart card interface, the data line returns to high impedance after this. The data line is
pulled high with a pull-up resistor.
4. The receiving side checks parity. When the data is received normally with no parity errors, the
receiving side then waits to receive the next data. When a parity error occurs, the receiving
side outputs an error signal (DE, low level) and requests re-transfer of data. The receiving
station returns the signal line to high impedance after outputting the error signal for a specified
period. The signal line is pulled high with a pull-up resistor.
5. The transmitting side transmits the next frame of data unless it receives an error signal. If it
does receive an error signal, it returns to step 2 to re-transmit the erroneous data.
15.4.4 Register Settings
Table 15.2 shows the bit map of the registers that the smart card interface uses. Bits shown as 1 or
0 must be set to the indicated value. The settings for the other bits are described below.
Table 15.2 Register Settings for the Smart Card Interface
Register
SCSMR
SCBRR
SCSCR
SCTDR
SCSSR
Address
H'FFFFFE80
H'FFFFFE82
H'FFFFFE84
H'FFFFFE86
H'FFFFFE88
Bit 7
C/A
BRR7
TIE
TDR7
TDRE
Bit 6
0
BRR6
RIE
TDR6
RDRF
SCRDR H'FFFFFE8A RDR7 RDR6
SCSCMR H'FFFFFE8C —
—
Note: Dashes indicate unused bits.
Bit 5
1
BRR5
TE
TDR5
ORER
RDR5
—
Bit 4
O/E
BRR4
RE
TDR4
FER/
ERS
RDR4
—
Bit 3
1
BRR3
0
TDR3
PER
RDR3
SDIR
Bit 2
0
BRR2
0
TDR2
TEND
RDR2
SINV
Bit 1
CKS1
BRR1
CKE1
TDR1
0
RDR1
—
Bit 0
CKS0
BRR0
CKE0
TDR0
0
RDR0
SMIF
1. Setting the serial mode register (SCSMR): The C/A bit selects the set timing of the TEND flag,
and selects the clock output state with the combination of bits CKE1 and CKE0 in the SCSCR.
Set the O/E bit to 0 when the IC card uses the direct convention or to 1 when it uses the inverse
convention. Select the on-chip baud rate generator clock source with the CKS1 and CKS0 bits
(see section 15.4.5, Clock).
Rev. 5.00 May 29, 2006 page 429 of 698
REJ09B0146-0500