Patent · US Expired

IC card

US4748320A · kind A · utility

155Cited by
1References
11Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 27, 1986
Grant dateMay 31, 1988
Priority date
Expiry dateOct 27, 2006

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F11/1068
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

In an IC (integrated circuit) card, a CPU (central processing unit) is connected to a data bus and an address bus. A data memory is connected to the data bus and the address bus. The data memory is a rewritable memory, such as EEPROM (electrically erasable programmable read only memory) or battery backed-up RAM (random access memory). The data memory is segmented into a predetermined number of sectors each consisting of predetermined bytes. An external processing device, such as a terminal device is connected to the data bus and the address bus, via a one-bit I/O line and a port. The terminal device supplies a processing instruction via the I/O line to the third port. The CPU receives the processing instruction via the data bus, analyzes the instruction, and reads out and executes the necessary program. The CPU supplies the results of each processing to the terminal device, by way of the data bus, the port and the I/O bus.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.