Memory with a reduced array data bus footprint

• US 10,366,743 B1
• Filed: 05/10/2018
• Issued: 07/30/2019
• Est. Priority Date: 05/10/2018
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Ho, Michael V., Moon, Byung S.
• Primary Examiner(s): Le, Thong Q
• Application Number:
  US15/976,716
• Time in Patent Office: 446 Days
• Field of Search: 36523003, 36523006, 36518904, 365200, 36518914, 36523001, 3652331, 36518511, 36518905, 365201, 365226, 36523008, 365 63, 365189011
• CPC Class Codes: G11C 11/4076 Timing circuits for regeneration management G11C11/406
• CPC Class Codes: G11C 11/4093 Input/output [I/O] data interface arrangements, e.g. data buffers
• CPC Class Codes: G11C 11/4094 Bit-line management or control circuits
• CPC Class Codes: G11C 11/4096 Input/output [I/O] data management or control circuits, e.g. reading or writing circuits, I/O drivers or bit-line switches
• CPC Class Codes: G11C 7/106 Data output latches
• CPC Class Codes: G11C 7/1087 Data input latches

Abstract

Memory devices and systems in which array data lines of a local data bus are shared between two or more memory bank groups in a memory array. In one embodiment, a memory device is provided, comprising a memory array, I/O gating circuitry, and a local data bus. The local data bus can include a plurality of array data lines shared between two or more memory bank groups of the memory array. The local data bus can electrically couple and transfer data between the two or more memory bank groups and the I/O gating circuitry. In some embodiments, one or more data latches can be electrically coupled to the local data bus to (i) transfer data off the local data bus to free the plurality of data lines for subsequent data transfers and/or (ii) match varying data propagation timings on the local data with column generations of the memory bank groups.

Claims

1. A memory device, comprising:

a memory array including two or more memory bank groups;

I/O gating circuitry;

a local data bus electrically coupling the I/O gating circuitry to the two or more memory bank groups; and

one or more data latches electrically coupled to the local data bus,

wherein—

the local data bus includes a plurality of array data lines shared between the two or more memory bank groups,

the plurality of shared array data lines is configured to transfer data between the I/O gating circuitry and each of the two or more memory bank groups,

data transferred over the plurality of shared array data lines between the I/O gating circuitry and a first memory bank group in the two or more memory bank groups has a first propagation delay,

data transferred over the plurality of shared array data line between the I/O gating circuitry and a second memory bank group in the two or more memory bank groups has a second data propagation delay different than the first propagation delay,

the memory device is configured to match column select generations for the first and the second memory bank groups with the first and the second propagation delays, and

the data latches are configured to transfer first data corresponding to a first access operation off of the local data bus to free up the local data bus to transfer second data corresponding to a second access operation.

2. The memory device of claim 1, wherein the first and the second access operations are read operations, and wherein the first and the second data are first read data and second read data, respectively.

3. The memory device of claim 2, wherein the first access operation is a read operation directed to the first memory bank group, and wherein the second access operation is a read operation directed to the second memory bank group.

4. The memory device of claim 2, wherein the one or more data latches are positioned at an edge of the memory array, and wherein the one or more data latches are configured to transfer the first read data off of the local data bus when the first read data exits the memory array.

5. The memory device of claim 1, wherein the first and the second access operations are write operations, and wherein the first and the second data are first write data and second write data, respectively.

6. The memory device of claim 5, wherein the first access operation is a write operation directed to the first memory bank group, and wherein the second access operation is a write operation directed to the second memory bank group.

7. The memory device of claim 5, wherein the one or more data latches are positioned at one or more locations proximate the two or more memory bank groups within the memory array, and wherein the one or more data latches are configured to transfer the first write data off of the local data bus when the first write data arrives at the one or more locations.

8. The memory device of claim 1, wherein—

the first memory bank group is positioned a first distance away from the I/O gating circuitry; and

the second memory bank group is positioned a second distance greater than the first distance away from the I/O gating circuitry such that the second data propagation delay is greater than the first data propagation delay.

9. The memory device of claim 1, wherein—

the memory device is configured to receive a clock signal;

a timing delay between the first and the second access operations is t_{CCD_S}; and

t_{CCD_S} is equivalent to four to eight cycles of the clock signal.

10. The memory device of claim 1, wherein the plurality of shared data lines of the local data bus includes a maximum of 64 array I/O data lines and a maximum of eight array data mask lines.

11. The memory device of claim 1, wherein—

the two or more memory bank groups are a first set of memory bank groups;

the memory device further comprises;

a second set of memory bank groups including two or more memory bank groups different than the two or more memory bank groups of the first set of memory bank groups, and

a second local data bus different than the first local data bus; and

the second local data bus electrically couples the second set of memory bank groups to the I/O gating circuitry.

12. The memory device of claim 1, wherein the memory device is a dynamic random access memory (DRAM) device.

13. A memory system, comprising:

a host device; and

a memory device including—

a memory array including two or more memory bank groups;

I/O gating circuitry;

a local data bus electrically coupling the I/O gating circuitry to the two or more memory bank groups; and

one or more data latches electrically coupled to the local data bus,

wherein—

the local data bus includes a plurality of array data lines shared between the two or more memory bank groups,

the plurality of shared array data lines is configured to transfer data between the I/O gating circuitry and each of the two or more memory bank groups,

data transferred over the plurality of shared array data lines between the I/O gating circuitry and a first memory bank group in the two or more memory bank groups has a first propagation delay,

data transferred over the plurality of shared array data line between the I/O gating circuitry and a second memory bank group in the two or more memory bank groups has a second data propagation delay different than the first propagation delay,

the memory device is configured to match column select generations for the first and the second memory bank groups with the first and the second propagation delays, and

the data latches are configured to transfer first data corresponding to a first access operation off of the local data bus to free up the local data bus to transfer second data corresponding to a second access operation.

14. The memory system of claim 13, wherein—

the memory device is configured to receive a clock signal;

a timing delay between the first and the second access operations is t_{CCD_S}; and

t_{CCD_S} is equivalent to four to eight cycles of the clock signal.

15. The memory system of claim 13, wherein the first access operation is directed to the first memory bank group, and wherein the second access operation is directed to the second memory bank group.

16. The memory system of claim 13, wherein—

the first memory bank group is positioned a first distance away from the I/O gating circuitry; and

the second memory bank group is positioned a second distance greater than the first distance away from the I/O gating circuitry such that the second data propagation delay is greater than the first data propagation delay.

17. An input/output (I/O) circuit for a memory device, the I/O circuit comprising:

I/O gating circuitry;

a local data bus having a plurality of array data lines configured to electrically couple the I/O gating circuitry to two or more memory bank groups in the memory device, the plurality of data lines including—

a plurality of array input/output (I/O) data lines; and

a plurality of array data mask lines; and

one or more data latches electrically coupled to the local data bus,

wherein—

each of the array data lines in the plurality of array data lines is configured to be shared between the two or more memory bank groups,

the plurality of array data lines is configured to transfer data between the I/O gating circuitry and each of the two or more memory bank groups,

data transferred over the plurality of array data lines between the I/O gating circuitry and a first memory bank group in the two or more memory bank groups has a first propagation delay,

data transferred over the plurality of shared array data lines between the I/O gating circuitry and a second memory bank group in the two or more memory bank groups has a second data propagation delay different than the first propagation delay, and

the data latches are configured to isolate first data corresponding to a first data transfer off of the local data bus to free up the local data bus to transfer second data corresponding to a second data transfer.

18. The I/O circuit of claim 17, wherein the plurality of array data lines includes a maximum of 64 array I/O data lines and a maximum of eight array data mask lines.

19. The I/O circuit of claim 17, wherein the memory device is a dynamic random access memory (DRAM) device.