Memory bank signal coupling buffer and method
View Patent ↗A memory array contains a plurality of banks coupled to each other by a plurality of data lines. Each of the data lines is divided into a plurality of segments within the array. Respective bidirectional buffers couple read data from one of the segments to another in a first direction, and to couple write data from one of the segments to another in a second direction that is opposite the first direction. The data lines may be local data read/write lines that couple different banks of memory cells to each other and to respective data terminals, digit lines that couple memory cells in a respective column to respective sense amplifiers, word lines that activate memory cells in a respective row, or some other signal line within the array. The memory array also includes precharge circuits for precharging the segments of respective data lines to a precharge voltage.
1. A memory device comprising:
a plurality of memory cells;
a plurality of data lines configured to provide respective signals within the plurality of memory cells, each of the data lines being divided into a plurality of data line segments;
a bidirectional buffer interposed in each of the data lines and connecting two of the data line segments to each other, each of the bidirectional buffers configured to provide data from one of the data line segments to the other in either of two opposite directions, wherein the bidirectional buffer is configured in a first mode to decouple the two of the data line segments from one another and in a second mode to provide a signal from one of the two of the data line segments to the other of the two of the data line segments; and
a precharge circuit configured to precharge each of the data line segments to a precharge voltage responsive to a precharge enable signal.
2. The memory device of claim 1 wherein the first mode is a precharge mode and occurs during at least a portion of a time the precharge enable signal is provided to the precharge circuit.
3. The memory device of claim 1 wherein the second mode is a read/write mode and occurs during at least a portion of a time the precharge enable signal is not provided to the precharge circuit.
4. The memory device of claim 1 wherein the bidirectional buffer comprises a transistor having a first source/drain terminal coupled to one of the two of the data line segments and a second source/drain terminal coupled to a reference voltage, and wherein the transistor is configured to turn off during the first mode, and wherein the transistor is configured to turn on during the second mode.
5. The memory device of claim 4 wherein the transistor is a first transistor and wherein the bidirectional buffer further comprises a second transistor, wherein a gate of the second transistor is coupled to the another of the two of the data line segments, and wherein a source/drain terminal of the second transistor is coupled to the gate of the first transistor.
6. The memory device of claim 5 , wherein the first transistor has a first conductivity type and the second transistor has a second conductivity type, wherein the second conductivity type is different than the first conductivity type.
7. The memory device of claim 1 , wherein the precharge circuit comprises a first transistor configured to precharge a first data line segment to the precharge voltage and a second transistor configured to precharge a second data line segment to the precharge voltage.
8. The memory device of claim 1 wherein the plurality of memory cells are divided into a plurality of banks of memory cells, and wherein each of the data lines comprise a respective local data read/write line that couples the plurality of banks to each other, each of the local data read/write lines being divided into a plurality of local data read/write line segments, and wherein one of the bidirectional buffers is interposed in each of the local data read/write lines connecting two of the local data read/write line segments to each other.
9. The memory device of claim 1 wherein the plurality of memory cells are arranged in rows and columns, and wherein each of the data lines comprise a respective digit line for each of the plurality of columns of memory cells, each of the digit lines being divided into a plurality of digit line segments, and wherein one of the bidirectional buffers is interposed in each of the digit lines connecting two of the digit line segments to each other.
10. The memory device of claim 1 wherein the plurality of memory cells are arranged in rows and columns, and wherein each of the data lines comprise a respective word line for each of the plurality of rows of memory cells, each of the word lines being divided into a plurality of word line segments, and wherein one of the bidirectional buffers is interposed in each of the word lines connecting at least two of the word line segments to each other.
11. A method comprising:
responsive to a signal indicative of a first mode:
disabling a bidirectional buffer to decouple two data line segments from one another; and
precharging the two data line segments to a precharge voltage; and
responsive to a signal indicative of a second mode:
enabling the bidirectional buffer to couple a signal from one of the two data line segments to another of the two of the data line segments.
12. The method of claim 11 , wherein said disabling a bidirectional buffer comprises turning off a transistor coupled between one of the data line segments and a reference voltage.
13. The method of claim 12 , further comprising during the second mode, coupling a signal from one of the two data line segments to another of the two of the data line segments responsive to a signal on the one of the two data line segments.
14. The method of claim 13 , wherein said coupling a signal comprises turning on the transistor.
15. The method of claim 11 wherein said precharging comprises turning on respective transistors coupled to the two data line segments.