Continuous interleave burst access

• US 7,210,020 B2
• Filed: 11/02/2005
• Issued: 04/24/2007
• Est. Priority Date: 07/03/1996
• Status: Expired due to Fees

• Current Assignee: Round Rock Research LLC
• Original Assignee: Micron Technology, Inc.
• Inventors: Blodgett, Greg A.
• Primary Examiner(s): PORTKA, GARY J
• Application Number:
  US11/265,460
• Publication Number:
  US 20060064540A1
• Time in Patent Office: 538 Days
• Field of Search: None
• US Class Current: 711/213
• CPC Class Codes: G06F 12/0215 with look ahead addressing means
• CPC Class Codes: G06F 12/0607 Interleaved addressing
• CPC Class Codes: G06F 13/1631 through address comparison

Abstract

A system is described which uses a burst access memory and a memory controller to anticipate the memory address to be used in future data read operations as requested by a microprocessor. Either the memory controller or the memory device initiates a burst read operation starting at a memory address generated thereby. The microprocessor can, therefore, wait to initiate a data read without suffering a time delay.

Claims

1. A method, comprising:

forming a synchronous memory device having addressable memory cells adapted to access a sequence of memory cells in response to an externally provided start address;

forming a microprocessor coupled to the synchronous memory device and adapted to initiate a first data read operation at a first memory cell address; and

forming a memory controller in the synchronous memory device adapted to produce a second start address in response to the externally provided start address and initiate a read operation in anticipation of a second data read operation at a new memory cell start address provided from the microprocessor, such that data stored at the second start address is output on an external data communication connection of the synchronous memory device following data output by the first data read operation to maintain an active data output stream between the first data read operation and a second data read operation requested by the microprocessor at the new memory cell start address for each first data read operation.

2. The method of claim 1, wherein forming the memory controller includes forming a comparator circuit adapted to compare the second memory cell address and the new memory cell address, and produce an output in response thereto.

3. The method of claim 1, wherein forming a memory controller includes forming the memory controller to produce the second memory cell address using an interleaved sequence.

4. The method of claim 1, wherein the microprocessor is adapted to withhold the new memory cell start address if the second start address and the new memory cell start address are the same.

5. The method of claim 1, wherein forming the synchronous memory device includes forming a burst extended data out dynamic random access memory (BEDO DRAM).

6. A method, comprising:

forming a microprocessor;

forming a burst access memory having addressable memory cells for providing data from a series of memory cells in response to a first read request from the microprocessor, the read request including a first start memory cell address; and

forming address generation circuitry included in the burst access memory for generating a second start memory cell address in response to the first start memory cell address and initiating a burst read operation in anticipation of a second read request from the microprocessor, such that data stored at the second start address is output on an external data communication connection of the burst access memory following data output by the first read request to maintain an active data output stream between the first read request and a second read request by the microprocessor at a new memory cell start address for each first read request.

7. The method of claim 6, wherein forming the burst access memory includes forming a comparator circuit adapted to compare the generated second start memory cell address and a memory cell address provided by the microprocessor.

8. The method of claim 6, wherein the microprocessor is adapted to withhold a request for data stored at a new memory cell address if the generated second start memory cell address is equal to the new memory cell address.

9. The method of claim 6, wherein forming the burst access memory includes forming full page length column sequence circuitry for outputting data stored at each column of a page of memory.

10. A method, comprising:

forming a burst access memory;

forming a processor to request a first read operation followed by a second read operation, the processor to provide a first start address to the burst access memory for the first read operation and to provide a second start address to the burst access memory for the second read operation;

forming an address generator to detect the first start address and provide an anticipated start address to the burst access memory in response to the first start address;

wherein the burst access memory is adapted to output a first burst output in response to the first start address and to output an anticipated burst output in response to the anticipated start address; and

wherein, when the anticipated start address corresponds to the second start address, the anticipated burst output follows the first burst output and maintains an active data output stream from the burst access memory from the first read operation to the second read operation.

11. The method of claim 10, wherein forming the address generator includes adapting the address generator to advance one or more most significant bits (MSB'"'"'s) of the first start address to provide the anticipated start address.

12. The method of claim 10, wherein forming the burst access memory includes forming the address generator.

13. The method of claim 10, further comprising:

forming a memory controller to communicate with the burst access memory, the memory controller including the address generator.

14. A method, comprising:

forming addressable memory cells;

forming a processor adapted to generate a first start address to read the memory cells; and

forming a memory controller adapted to receive the first start address, to output a first data series from the addressable memory cells to the processor in response to receiving the first start address, to generate an anticipated start address in response to receiving the first start address, and to output an anticipated data series from the addressable memory cells such that the anticipated data series follows the first data series to maintain an active data output stream from the addressable memory cells to the processor.

15. The method of claim 14, wherein the memory controller is adapted to advance one or more most significant bits (MSB'"'"'s) of the first start address to provide the anticipated start address.

16. The method of claim 14, wherein the memory controller is adapted to generate a linear sequence of addresses for the first data series and the anticipated data series.

17. The method of claim 14, wherein the memory controller is adapted to generate an interleaved sequence of addresses for the first data series and the anticipated data series.

18. The method of claim 14, wherein the processor is adapted to generate a second start address and the memory controller is adapted to compare the second start address to the anticipated start address.

19. The method of claim 18, wherein the memory controller is adapted to provide the anticipated start address to the processor for comparison to a second start address.

20. A method, comprising:

forming a memory device, including addressable memory cells and control circuitry to provide burst outputs from the addressable memory cells in response to an address;

forming a processor to request a first burst read operation from the addressable memory cells followed by a second burst read operation from the addressable memory cells, the processor to provide a first address to the control circuitry of the memory device for the first burst read operation and to provide a second address to the control circuitry of the memory device for the second burst read operation, the memory device to output a first burst output in response to the first address; and

forming an address generator to provide an anticipated address to the memory device based on the first address such that the memory device outputs an anticipated burst output, wherein when the anticipated address corresponds to the second address, the memory device is adapted to maintain an active data stream for the first burst read operation and the second burst read operation.

21. The method of claim 20, further comprising:

forming a memory controller to communicate with the memory device, the memory controller including the address generator.

22. The method of claim 20, wherein forming the memory device includes forming an address generator.

23. A method, comprising:

forming a microprocessor; and

forming a synchronous memory device, including;

forming a memory cell array;

forming address circuitry coupled to the memory cell array; and

forming control circuitry coupled to the address circuitry and to the memory cell array;

wherein the microprocessor is adapted to provide a first start address to the synchronous memory device;

wherein the control circuitry is adapted to provide a first burst output from the memory cell array to the microprocessor in response to the first start address;

wherein the control circuitry is adapted to provide an anticipated start address in response to the first start address in anticipation of a second start address from the microprocessor;

wherein, in response to the anticipated start address, the control circuitry is adapted to initiate an anticipated burst output from the memory cell array; and

wherein the anticipated burst output follows the first burst output and maintains an active data output stream to the microprocessor for the first externally-provided start address and the second externally-provided start address.

24. The method of claim 23, wherein forming the control circuitry includes forming a comparator circuit adapted to compare the second start address and the anticipated cell address and to produce an output in response thereto.

25. The method of claim 23, wherein forming the synchronous memory device further includes forming a comparator circuit adapted to compare the second start address and the anticipated cell address and to produce an output in response thereto.

26. The method of claim 23, wherein the microprocessor is adapted to produce the second start address using an interleaved sequence.

27. The method of claim 23, wherein the microprocessor is adapted to produce the second start address using a linear sequence.

28. The method of claim 23, wherein the microprocessor is adapted to withhold the second start address if the second start address and the anticipated start address are the same.

29. The method of claim 23, wherein forming the synchronous memory device includes forming a burst extended data out dynamic random access memory (BEDO DRAM).

30. A method, comprising:

forming a microprocessor; and

forming a synchronous memory device, including;

forming addressable memory cells; and

forming a memory controller coupled to the memory cells;

wherein the microprocessor is adapted to provide read requests to the synchronous memory device;

wherein the memory controller is adapted to output a data series from the addressable memory cells to the microprocessor in response to the read requests beginning with a start address contained within the read requests;

wherein the memory controller is adapted to output a first data series to the microprocessor in response to a first external read request beginning with a first start address contained within the first external read request;

wherein, in response to the first start address, the memory controller is adapted to initiate an output of an anticipated data series to the microprocessor beginning with an anticipated start address in anticipation of a second read request from the microprocessor;

wherein, in response to the second read request from the microprocessor that begins with a second start address, the memory controller is adapted to compare the second start address to the anticipated start address and to continue to output the anticipated data series as a second data series when the second start address is the same as the anticipated start address; and

wherein the second data series follows the first data series to maintain an active data output stream on the external output connection.

31. The method of claim 30, wherein forming the memory controller includes forming a comparator circuit adapted to compare the second start address and the anticipated cell address and to produce an output in response thereto.

32. The method of claim 30, wherein forming the synchronous memory device further includes forming a comparator circuit adapted to compare the second start address and the anticipated cell address and to produce an output in response thereto.

33. The method of claim 30, wherein the microprocessor is adapted to produce the second start address using an interleaved sequence.

34. The method of claim 30, wherein the microprocessor is adapted to produce the second start address using a linear sequence.

35. The method of claim 30, wherein the microprocessor is adapted to withhold the second start address if the second start address and the anticipated start address are the same.

36. The method of claim 30, wherein forming the synchronous memory device includes forming a burst extended data out dynamic random access memory (BEDO DRAM).

37. A method, comprising:

forming a burst access memory, including;

forming memory cells; and

forming address generation circuitry coupled to the memory cells; and

forming a microprocessor coupled to the memory cells and to the address generation circuitry,

wherein the microprocessor is adapted to produce read requests for data stored in the memory cells;

wherein each read request includes a start memory cell address;

wherein, in response to a first start memory cell address from a first read request, the address generation circuitry is adapted to produce an anticipated start memory cell address in anticipation of a second read request from the microprocessor;

wherein the burst access memory is adapted to provide a first data series in response to the first start memory cell address and an anticipated data series in response to the anticipated start memory cell address; and

wherein the anticipated data series follows the first data series to maintain an active data output stream.

38. The method of claim 37, wherein forming the burst access memory includes forming a comparator circuit adapted to compare the anticipated start memory cell address and a second start memory cell address provided by the microprocessor as part of the second read request.

39. The method of claim 37, wherein the microprocessor is adapted to withhold the second read request if the anticipated start memory cell address is equal to a second start memory cell address provided by the microprocessor as part of the second read request.

40. The method of claim 37, wherein forming the burst access memory includes forming full page length column sequence circuitry for outputting data stored at each column of a page of memory.