Abstract:
The invention relates to a microprocessor circuit for organising access to data or programmes that have been stored in a memory. Said circuit comprises at least one microprocessor, a memory for an operating system and at least one memory for free programming using individual external programmes. The memory used for free programming has several memory areas containing corresponding address spaces, a qualifier being assigned to each address space. The microprocessor circuit also has means, which prior to the respective addressing of a memory area, load each qualifier assigned to a respective memory area into a first auxiliary register and load the qualifier of the addressed memory area into a second auxiliary register and which then compare the first and second auxiliary registers. At least one bit sequence containing access authorisations is also assigned to each address space of a memory area, which allows code commands and sensitive data to be protected from write access emanating from external programmes.
Abstract:
The invention relates to a method for controlling the interrupt process and/or recording of execution data of a program in a microcontroller (1), whereby a debugging unit (3) is informed by way of a selection attribute associated with a defined program instruction whether a program may be interrupted and/or the pertaining execution data may be recorded while a program instruction is being executed. The invention also relates to a microcontroller (1) which, in addition to the switching circuits and data memories of a microcontroller (2) to be emulated, comprises an arrangement for controlling the interrupt process and/or recording of execution data of a program. The arrangement is characterized in that it comprises a debugging unit (3) and a control logic (5). Said control logic (5) uses a defined selection attribute associated with defined program instructions for deciding whether, in place of a program instruction in a program, the program flow is interrupted and/or the execution data are recorded.
Abstract:
The invention relates to a method for controlling the mapping of a logical address of a logical address space to a physical address of a physical address space (20). Said method involves the following steps: a first physical address and a corresponding memory cell, which are associated by the mapping (30) of a logical address, are determined; the memory cell is checked for serviceability; and the mapping (30) is modified if the check reveals that the memory cell is not serviceable, in such a way that the logical address is mapped to a second physical address in the physical address space (20). In this way, access to a physical memory is carried out by means of logical addresses which are mapped to the physical addresses of the physical memory, i.e. virtual memory addressing is used in order to mask out non-serviceable memory cells in a simple and effective manner.
Abstract:
The invention relates to a method for determining a physical address from a virtual address, whereby a mapping rule is implemented between the virtual address and the physical address in the form of a hierarchical tree structure comprising compressed nodes. According to said method, a compression indicator contained in the mapping rule is first read (1300). Then, a section of the virtual address, which is assigned to the node level under consideration, is read (1310). An entry in the node list of the node currently under consideration is determined (1320) using the compression indicator and the virtual address section. The entry that has been determined is read (1330) and the physical address can then be directly determined, if the node level under consideration was the lowest node level in the hierarchy. If there are additional node levels to be processed, the previous steps are repeated for the determination (1340) of the physical address for compressed nodes of lower hierarchy levels, until the lowest node level in the hierarchy has been reached. For addressing schemes, in which the virtual address space is greater than the physical address space, storage space can be saved by the compression of the node lists, which in their uncompressed form contain a number of zero entries, thus providing space for other data.
Abstract:
The invention relates to a microprocessor circuit comprising a control unit, a memory for free programming with at least one program comprising functions, a stack for the intermediate storage of data and a register bank comprising at least one register which contains an auxiliary register storing a number of bits. Each bit is associated with one of the registers in the register bank and indicates whether or not each register in the register bank contains information.
Abstract:
Secure data processing unit has a data and program memory (1), a command controller (2) and a control unit (3) for controlling a multiplicity of the function steps of the command controller. An additional empty function generator (4) is provided that generates random empty functions and thus also causes empty input-output processes. An independent claim is made for a method for securing a data processing unit against electronic eavesdropping in which additional empty transmit and receive processes are initiated.
Abstract:
Secure data processing unit has a data and program memory (1), a command controller (2) and a control unit (3) for controlling a multiplicity of the function steps of the command controller. An additional empty function generator (4) is provided that generates random empty functions and thus also causes empty input-output processes. An independent claim is made for a method for securing a data processing unit against electronic eavesdropping in which additional empty transmit and receive processes are initiated.
Abstract:
An efficient method for protecting entry addresses in computer programs allows direct jumps to permissible entry addresses. The permissible entry addresses are identified with a correlation of data which are not provided within the same individual instruction. By organizing the program code, the compiler or linker ensures that only legal entry addresses satisfy this correlation.
Abstract:
An efficient method for protecting entry addresses in computer programs allows direct jumps to permissible entry addresses. The permissible entry addresses are identified with a correlation of data which are not provided within the same individual instruction. By organizing the program code, the compiler or linker ensures that only legal entry addresses satisfy this correlation.