SMARTCARDS

A smartcard is a small embedded microcontroller with a set of metal contacts or an antenna to enable the information stored on it to be read from, or written to, from external devices. The smartcard is either used as the small smartcard itself, or contained with a larger credit card sized holder. Examples of smartcards are:

Credit / Payment Cards
Mobile Phone SIM cards
Pay for view TV Cards
Security Cards
Travel Cards
Medical Cards

The external device can be anything from a computer, a mobile phone, a credit or payment card reader, a subscription service reader (such as for a pay for view TV service), a security card reader, a medical card reader, a transport card reader or a PDA.

Smartcard Microcontrollers.

The microcontrollers used for smartcards range from 8-bit through to 32-bit architectures. The majority of smartcards currently use embedded 8-bit microcontrollers, simply because the tasks the smartcards perform do not generally require any more processing power. Examples of smartcard microcontroller architectures include:

Microchip PIC (e.g. PIC 16F84, 12C508)
Motorola 6805
Hitachi H8/310
Intel 8051
Thomson ST8

Smartcard Memory.

Smartcard memory usually takes the form of ROM (Read Only Memory) for the Operating System, EEPROM (Electrically Erasable Programable Read Only Memory) for the Smartcard application(s), and RAM (Random Access Memory) for any temporary storage. The smartcard memory is either contained on the embedded microcontroller itself, or in a separate embedded memory IC such as a 24LC16B.

The Smartcard memory sizes are typically from 1-16 Kbytes of EEPROM, 100-1024 bytes of RAM, and 1-16 Kbytes of ROM.

The ISO 7816 Smartcard Standard.

Probably the most widely used smartcard standard is the ISO 7816 standard, which refers to the physical, electrical, dimensional and geometrical characteristics required for a smartcard to meet the ISO 7816 standard.

For an ISO 7816 defined smartcard, there are 8 electrical contacts, not all of which are connected to the embedded IC, and thus not all contacts are neccessarily used. The contacts are referred to as C1 to C8.

ISO 7816 Smartcard Electrical Contacts.

Contact	Name	Function
C1	V_CC	Power connection through which operating power is supplied to the microprocessor chip in the card
C2	RST	Reset line through which the IFD can signal to the smart card's microprocessor chip to initiate its reset sequence of instructions
C3	CLK	Clock signal line through which a clock signal can be provided to the microprocessor chip. This line controls the operation speed and provides a common framework for data communication between the IFD and the ICC
C4	RFU	Reserved for future use
C5	GND	Ground line providing common electrical ground between the IFD and the ICC
C6	V_PP	Programming power connection used to program EEPROM of first generation ICCs
C7	I/O	Input/output line that provides a half-duplex communication channel between the reader and the smart card
C8	RFU	Reserved for future use

Smartcard Contact Pad Layouts

The following images indicate typical smartcard contact pad layouts (please note, the layouts are not to scale):

Pad Layout	Contact ID	Pin ID	Details
			Image 1 -
			Image 2 -
			Image 3 - This smartcard contact pad layout is a typical Mobile Phone SIM Smartcard pad layout.
			Image 4 - This smartcard contact pad layout indicates a pad layout for a PIC16F84 microcontroller based Smartcard.
			Image 5 - This smartcard contact pad layout is a typical Mobile Phone SIM Smartcard pad layout, such as for a BT Cellnet SIM card.