Specifications

28
Smart card
interface
mode (SIM)
In this mode the SCI conforms to a sub-
set ISO7816-3. This standard is used to
communicate with so called smart cards,
which are frequently used in banking
applications (electronic money),GSM
phones and many other applications like
building entry control or for ‘loyalty
cards’. Because these applications are
expected to grow very rapidly in the
next few years,Hitachi has equipped all
H8S devices with SCI’s that can be set to
SIM mode.
According to ISO 7816-3,the
communication used is asynchronous,
half-duplex (i.e.only either the host or
the smart card transmits at a time) and
with even parity always. Also, after
transmission of the data and within the
Vcc
Data Line
TxD0
RxD0
SCK0
Px (Port)
Reset Line
Clock Line
IC card
H8S
MOSFET
I/O
I/O
CLK
RST
Vcc
Vcc
time normally used as stop bits,
ISO7816-3 implements an error bit.
That means,that a low level on the
RxD/TxD line at a particular position
after the data bits has to be recognised
by the transmit side as an error in
reception on the receive side. The
transmitting side shall respond by
retransmitting the last data. The SCI in
SIM mode also supports direct and
inverse convention as set out by ISO
7816-3.
The physical interface between the host
and the smart card comprises the
RxD/TxD pins tied together and then
connected to the I/O pin of the smart
card,a clock that must be provided to
the smart card and initially has to be 372
times the baudrate and a reset signal.
Reset is not tied to the reset pin of the
host microcontroller, but is connected to
a general purpose IO pin of the host,
thus putting the smart card’s reset under
host software control.
Also, a general purpose IO of the host is
used to control a MOSFET that turns on
and off the power to the smart card. In
banking applications another MOSFET
may be used to power a card ejection
mechanism.
H8/3048 and first-generation H8S
products have the following limitations:
1) The only available speed of the SIM
is the default value of clock/372 and
2) There is no support for the so called
protocol
”
T=1“
Latest H8S products add 3 new speeds
(clock/32,64 and 256) and support for
”
T=1“.These are the H8S series
H8S/222x,H8S/223x, H8S/231x,
H8S/232x,H8S/263x and all future H8S
products.
Figure 20