SH7730 Datasheet, PDF (899/1188 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7780 Series

Section 25 SIM Card Module (SIM)
Hence the receive margin can be expressed as follows.
Formula for receive margin in smart card mode:
M = ( 0.5
1)
2N
( L - 0.5 ) F
D 0.5 _{( L + F ) × 100%}
N
where
M: Receive margin (%)
N: Ratio of the bit rate to the clock (N = 372)
D: Clock duty (D = 0 to 1.0)
L: Frame length (L = 10)
F: Absolute value of the deviation of the clock frequency
In the above formula, if F = 0 and D = 0.5, then the receive margin is as follows.
When D = 0.5, F = 0,
M = (0.5 − 1/2 × 372) × 100%
= 49.866%.
(2) Retransmit Operation
Retransmit operations when the smart card interface is in receive mode and in transmit mode are
described below.
• Retransmission when the smart card interface is in receive mode (T = 0)
Figure 25.8 shows retransmit operations when the smart card interface is in receive mode.
(a) If an error is detected as a result of checking the received parity bit, the PER bit in SCSSR
is automatically set to 1. At this time, if the RIE bit in SCSCR is set to enable, an ERI
request is issued. The PER bit in SCSSR should be cleared to 0 before the sampling timing
for the next parity bit.
(b) The RDRF bit in SCSSR is not set for frames in which a parity error occurs.
(c) If no error is detected as a result of checking the received parity bit, the PER bit in SCSSR
is not set.
(d) If no error is detected as a result of checking the received parity bit, it is assumed that
reception was completed normally, and the RDRF bit in SCSSR is automatically set to 1. If
the RIE bit in SCSCR is 1 and the EIO bit is 0, an RXI request is generated.
(e) If a normal frame is received, the pin retains its high-impedance state at the timing for
transmission of error signals.
Rev. 1.00 Sep. 19, 2007 Page 851 of 1136
REJ09B0359-0100