Universal memory device having a profile storage unit
View Patent ↗A universal memory device is presented that provides adaptability to existing hardware and software environments. The memory can “mimic” existing memory technology combining the advantages of integrating all memory capacity into one single technology and still providing the implicit protections and access characteristics known from the different existing memory technologies. The memory device comprises a memory having low-latency, rewritable, non-volatile memory cells, a profile storage unit connected with the memory and comprising access information allocated to a set of request information elements (request profile), such that the access information indicates whether an access request to said memory, the access request having the request profile, is to be allowed or rejected, and an access control unit communicating with the profile storage unit and the memory, and adapted to allow or reject an incoming access request in dependence on the access information allocated to the request profile of the access request.
1. A memory device comprising:
an interface for receiving access requests, the interface having an address output to an address path and a data output to a data path, wherein address information is carried on the address path and data for writing to memory or data read from memory is carried on the data path;
a memory cell array having a plurality of low-latency, rewritable, non-volatile memory cells forming at least one memory section;
a word-select unit connected in the data path and to the address path and between the interface and the memory cell array to provide column selection;
a section-select unit connected to the address path and between the interface and the memory cell array to provide row selection;
wherein both the word-select unit and the section-select unit select a respective column and row of the memory cell array in response to the address information;
a profile storage unit connected to said interface comprising a plurality of request profiles that each represent a profile of an access request, wherein each request profile includes:
a set of request information elements, wherein at least one of the request information elements indicates whether an access request is a read request or a write request; and
access flags, whose state indicates whether a corresponding access request is allowed to access the memory or not allowed to access the memory, the access flags comprising write protect flags and read protect flags;
an access control unit connected to said profile storage unit and said memory and configured to allow or reject an access request;
wherein said profile storage unit selects an access flag that corresponds to a request profile in response to an access request that fits the request profile; and
wherein the access control unit allows or rejects an access request in response to the access flag that is selected by the profile storage unit and wherein a write request that violates a write access flag is ignored and a read request that violates a read access flag results in a fixed answer and wherein a violation triggers an interrupt pin on the interface.
2. The memory device of claim 1 wherein the profile storage unit comprises a set of access flags, one access flag for each row address, such that each access flag governs the access to one row of the memory cell array.
3. The memory device of claim 2 wherein the access flags are fast read-out state registers.
4. The memory device of claim 1 wherein the access control unit operates in the data path to admit or reject a flow of data to or from the memory cell array depending on the state of the corresponding access flag it receives from the profile storage unit.
5. The memory device of claim 1 further comprising a memory mapped interface and an I/O mapped interface connected to provide access to the memory cell array.
6. The memory device of claim 5 wherein pins of the memory device are shared by the memory mapped and I/O mapped interfaces.