The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 13, 1996
Filed:
Jan. 14, 1994
Thomas O Holtey, Newton, MA (US);
Bull HN Information Systems Inc., Billerica, MA (US);
Abstract
An application memory card system includes a secure memory card which can be operatively connected to communicate with a host mainframe microprocessor or hand held device host microprocessor via a standard interface. The secure memory card contains an application processor and an access control microprocessor (ACP), each of which connect through an internal bus to a number of non-volatile addressable memory chips, each organized into a plurality of blocks. Each microprocessor has an additional control signal line included in a control bus portion of its bus for specifying 'Execute' access. An access discrimination logic unit which connects to the internal bus and to the non-volatile memory includes an access by type memory writable by the application processor under the control of the ACP for maintaining security. The access discrimination logic unit combines the 'Execute' control access signal from a microprocessor with a signal designating the microprocessor source (e.g. external or internal) to define the type of memory access requested and transfers a control enabling signal as a function of the state of the selected stored access control bit indicating if the requested access is allowed to the addressed block.