Single chip microcomputer having unauthorized memory space access protection
US5067077A · kind A · utility
44Cited by
9References
8Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 19, 1991 |
| Grant date | Nov 19, 1991 |
| Priority date | — |
| Expiry date | Mar 19, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F12/0638
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A single-chip microcomputer connectable to an external memory for expanding the address space, and having a first mode of operation in which the available memory region is both the region of an internal ROM and the external memory, and having a second mode of operation in which the available memory region is the region of the external memory only. An inhibiting device is provided for inhibiting the switching from the second mode to the first mode, thereby ensuring that the contents of the internal ROM cannot be read-out.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.