Specifications

124 Intel
®
Atom™ processor CE4100 Ref# 420826
Platform Design Guide
Intel Confidential
8.10 Smart Card Interface
The Intel
®
Atom™ processor CE4100 has two identical and independent smart card
interfaces. The smart card connector can be directly connected to the Intel
®
Atom™
processor CE4100.
When the card is inserted, it activates the card presence switch in the card socket, which is
periodically polled by the software via the SC_INSERT pin. If insertion is detected, the
software may apply the power supply voltage to the card by toggling SC_VEN and SC_VSEL,
and initiate the reset sequence according to ISO7816-3. During this phase, the card type,
protocol and data polarity is detected. When the card is removed, the power supply is
immediately disabled to avoid potential card damage by the hardware, and the CARD_DET
interrupt is generated to notify the software.
Table 8-20. Smart Card Interface External Signals
Signal
Name
Npins I/O Description
SCn_CLK 1 O Card Clock Signal: When the card is inserted, this pin outputs the
programmable clock frequency for the card. The output levels are 3.3V
CMOS compatible.
SCn_DIO 1 I/O Card Data I/O: This bidirectional pin is used to transfer serial data to
and from the smart card. Although its output levels are 3.3V CMOS
compatible, this input is 5V tolerant.
SCn_RST 1 O Card Reset Signal: The reset pin initiates the process of reset and card
type discovery. The pin can be set and cleared by software to support
both positive and negative reset polarity. When the card is removed,
reset signal goes low.
SCn_VSEL 1 O Card Voltage Select: This pin controls the power supply voltage
applied to the smart card.
SCn_VEN 1 O Card Power Enable: When high, this pin enables the power supply for
the smart card, and the 3.3V or 5V power is applied depending on the
state of SCn_PWR_CTRL pin.
SCn_INSERT 1 I Card Insertion Detect: This pin senses the card insertion detect switch,
which can be normally closed or normally open. The active state of the
switch is configurable by INSERT_POL bit in Card Control Register
(CCR). When the card is removed, the power supply is immediately
disabled.
The smart card communicates with the host via a serial bidirectional interface in byte mode
(T=0) or block mode (T=1), according to ISO 7816-3 protocol.