Programmable resistance memory with interface circuitry for providing read information to external circuitry for processing
View Patent ↗A memory includes an interface through which it provides access to memory cells, such as phase change memory cells. Such access permits circuitry located on a separate integrated circuit to provide access signals, including read and write signals suitable for binary or multi-level accesses.
1. An apparatus comprising:
an array of memory cells; and
interface circuitry implemented on the same integrated circuit as the array of memory cells, the interface circuitry configured to provide to an external circuit at least one signal indicative of the storage state of a selected memory cell for storage level evaluation, the storage level evaluation including dividing the difference between two applied voltages impressed across a selected memory cell by the difference between two resultant currents, the at least one signal generated in response to the application of a read signal.
2. The apparatus of claim 1 , further comprising analog-to-digital conversion circuitry configured to convert a signal representative of the state of an accessed memory cell.
3. The apparatus of claim 1 , further comprising error detection and correction circuitry configured to detect and correct storage errors associated with the memory cells.
4. The apparatus of claim 1 , wherein the at least one signal is further provided to an external circuit for error detection and correction by the external circuit.
5. The apparatus of claim 1 , wherein the at least one signal is further provided to an external circuit for analog-to-digital conversion by the external circuit.
6. The apparatus of claim 1 , wherein the storage level evaluation is binary storage level evaluation.
7. The apparatus of claim 1 , wherein the storage level evaluation is multi-level storage level evaluation.
8. The apparatus of claim 1 , wherein the interface circuit is configured to accept access pulses from an external circuit.
9. The apparatus of claim 8 , wherein the access pulses are READ pulses.
10. The apparatus of claim 8 , wherein the access pulses are WRITE pulses.
11. The apparatus of claim 10 , wherein the WRITE pulses are binary WRITE pulses for memory chip conversion to analog signals.
12. The apparatus of claim 10 , wherein the WRITE pulses are multi-level WRITE pulses.
13. The apparatus of claim 8 , wherein the access pulses are current pulses.
14. The apparatus of claim 8 , wherein the access pulses are voltage pulses.
15. An apparatus, comprising:
interface circuitry configured to encode memory signals received from a memory array located on a separate integrated circuit, the interface circuitry further configured to evaluate storage levels associated with the memory signals received from the memory array, the storage level evaluation including dividing the difference between two applied voltages impressed across a selected memory cell by the difference between two resultant currents; and
circuitry configured to interface with a system bus.
16. The apparatus of claim 15 , wherein, the interface circuitry configured to encode memory signals is further configured to convert at least one signal from the memory array from analog to digital form.
17. The apparatus of claim 15 , wherein, the interface circuitry configured to encode memory signals is further configured to perform error correction and detection upon the at least one signal from the memory array.
18. An electronic system comprising:
an array of memory cells;
interface circuitry implemented on the same integrated circuit as the array of memory cells, the interface circuitry configured to provide to an external circuit at least one signal indicative of the storage state of a selected memory cell for storage level evaluation, the storage level evaluation including dividing the difference between two applied voltages impressed across a selected memory cell by the difference between two resultant currents, the at least one signal generated in response to the application of a read signal to an external circuit for encoding by the external circuit;
interface circuitry formed in a circuit external to the memory array configured to encode memory signals received from a memory array located on a separate integrated circuit; and
circuitry configured to interface with a system bus.
19. The system of claim 18 , further comprising, controller circuitry configured to access the array of memory devices through the system bus and interface circuitry formed in a circuit external to the memory array.
20. The system of claim 19 , further comprising a transceiver.
21. The system of claim 20 , wherein the electronic system is configured as a radio frequency identification device (RFID).
22. The system of claim 20 , wherein the electronic system is configured as a cellular telephone.
23. The system of claim 19 , wherein the electronic system is configured as a computer.