Magnetic random access memory array having bit/word lines for shared write select and read operations
View Patent ↗A random access memory array includes random access memory elements arranged in a rows and columns. The elements of each row have a word line and a write digit line and the elements of each column have a bit line and a write bit line. A first selection circuit/transistor for each row has a first source-drain path coupled in the write digit line and a gate terminal coupled to the word line. A second selection circuit/transistor for each column has a second source-drain path coupling in the write bit line and a gate terminal coupled to the bit line. A first write signal is applied to one word line to actuate the first selection circuit/transistor for the row corresponding to that one word line and cause a write current to flow through the first source-drain path of the actuated first selection circuit/transistor and the corresponding write digit line to write data into certain memory elements in that row. A second write signal is applied to one bit line to actuate the second selection circuit/transistor for the column corresponding to that one bit line and cause a write current to flow through the second source-drain path of the actuated second selection circuit/transistor and the corresponding write bit line to write data into at least one memory element in that column.
1. A magnetic random access memory array, comprising:
a plurality of rows and columns of magnetic random access memory elements, the elements of each row having a word line and a write digit line and the elements of each column having a bit line and a write bit line; and
a selection circuit for each row having a source-drain path coupled in the write digit line and a gate terminal coupled to the word line.
2. The array of claim 1 further comprising:
a write driver circuit coupled to the word line; and
a word line select circuit coupled to the word line.
3. The array of claim 2 further comprising:
a multiplexer having first and second ports on a first side coupled to the write driver circuit and the word line select circuit, respectively, and a third port on a second side coupled to the word line.
4. The array of claim 3 further including a multiplexer selection signal coupled to the multiplexer for selectively connecting the first/second ports to the third port in response to a write/read signal.
5. The array of claim 4 wherein the write/read signal is derived from a write/read operational mode of the array.
6. The array of claim 1 , wherein:
a write signal applied to one word line actuates the selection circuit for the row corresponding to that one word line and causes a write current to flow through the source-drain path of the actuated selection circuit and the corresponding write digit line to write data into certain memory elements in that row.
7. The array of claim 1 wherein the word line is a segmented word line comprised of a global word line and a plurality of local word lines.
8. The array of claim 1 wherein the write digit line is a segmented write digit line comprised of a global write digit line and a plurality of local write digit lines, the selection circuit for selecting one of the local write digit lines.
9. The array of claim 1 wherein the word line is a segmented word line comprised of a global word line and a plurality of local word lines and the write digit line is a segmented write digit line comprised of a global write digit line and a plurality of local write digit lines, the selection transistor for selecting one of the local write digit lines.
10. A memory, comprising:
a memory array, comprising:
a plurality of rows and columns of magnetic random access memory elements, the elements of each row having a word line and a write digit line and the elements of each column having a bit line and a write bit line; and
a selection transistor for each row having a source-drain path coupled in the write digit line and a gate terminal coupled to the word line; and
a write driver circuit for each row having an output selectively coupled to the gate terminal of the selection transistor for a corresponding word line; and
a word line select circuit for each row having an output selectively coupled to the gate terminal of the selection transistor of a corresponding word line.
11. The memory of claim 10 further comprising:
a row decoder outputting a row decode control signal for each row in the array, each row decode control signal coupled to control actuation of the write driver circuit and word line select circuit.
12. The memory of claim 10 further comprising:
a multiplexer for each row having first and second ports on a first side coupled to the outputs of write driver circuit and the word line select circuit, respectively, for the corresponding word line and a third port on a second side coupled to the corresponding word line.
13. The memory of claim 12 each row further including a multiplexer selection signal coupled to the multiplexer for selectively connecting the first/second ports to the third port in response to a write/read signal derived from a write/read operational mode of the array.
14. The memory of claim 10 , wherein:
a write signal applied to one word line actuates the selection transistor for the row corresponding to that one word line and causes a write current to flow through the source-drain path of the actuated selection transistor and the corresponding write digit line to write data into certain memory elements in that row.
15. The memory of claim 10 wherein each word line is a segmented word line comprised of a global word line and a plurality of local word lines.
16. The memory of claim 10 wherein each write digit line is a segmented write digit line comprised of a global write digit line and a plurality of local write digit lines, the selection circuit for selecting one of the local write digit lines.
17. The memory of claim 10 wherein the word line is a segmented word line comprised of a global word line and a plurality of local word lines and the write digit line is a segmented write digit line comprised of a global write digit line and a plurality of local write digit lines, the selection transistor for selecting one of the local write digit lines.