Efficient word lines, bit line and precharge tracking in self-timed memory device
View Patent ↗A memory device for efficient word line, bit line and precharge tracking is provided. The memory device includes a memory array, one or more address decoders, a word line driver, a plurality of sense amplifiers, a reference word line column, a reference bit line column, and a control circuit. The control circuit generates a control signal to perform read and write operations on the memory device. The address decoder selects a bit line and a word line. The selected word line is activated by the word line driver. While the reference word line column is used for vertical tracking of the word line, the reference bit line column is used for vertical tracking of the bit line. The sense amplifiers are activated to read the bit line.
1. A memory device including a memory array, the memory array comprising a plurality of bit line columns comprising a plurality of bit lines, each of the plurality of bit line columns connected to a plurality of memory cells, wherein each of the plurality of memory cells are connected to a plurality of word lines, the memory device comprising:
one or more address decoders for selecting at least one of the plurality of bit lines and word lines;
a word line driver for enabling at least one of the plurality of word lines;
a plurality of sense amplifiers for sensing the plurality of bit lines, wherein each of the plurality of sense amplifiers is associated with a corresponding bit line of the plurality of bit lines;
a reference word line column for vertical tracking of the at least one of the plurality of word lines using a first predefined loopback;
a reference bit line column comprising a reference bit line for vertical tracking of at least one of the plurality of bit lines using a second predefined loopback; and
a control circuit comprising:
a dummy decoder for generating a reference word line signal;
a first programmable delay circuit connected to the dummy decoder for programming delay of the reference word line signal; and
a sense amplifier enable driver for activating a sense amplifier of the plurality of sense amplifiers, wherein fan-out of the sense amplifier enable driver is equal to a fan-out of the word line driver.
2. The memory device of claim 1 , wherein the second predefined loopback is about fifty (50) percent loopback of a reference bit line signal.
3. The memory device of claim 1 , further comprising:
a word line clock generator for generating a word line clock signal, wherein the word line clock signal activates the at least one of the plurality of word lines; and
a reference word line clock generator for generating a reference word line clock signal, wherein the reference word line clock signal enables vertical tracking of the at least one of the plurality of word lines using the first predefined loopback.
4. The memory device of claim 3 , wherein the first predefined loopback is about fifty (50) percent loopback of the reference word line clock signal.
5. The memory device of claim 3 , wherein the reference word line column further comprises a plurality of dummy blocks, wherein the plurality of dummy blocks being equal in number to the number of the one or more address decoders, and wherein each address decoder of the one or more address decoders receives the word line clock signal.
6. The memory device of claim 1 , wherein the reference bit line column further comprises a plurality of reference memory cells, the plurality of reference memory cells being equal in number to the number of memory cells connected to at least one of the plurality of bit lines.
7. The memory device of claim 1 , wherein the control circuit further comprises a precharge driver for precharging the reference bit line and at least one of the plurality of bit lines to a first predefined threshold voltage.
8. The memory device of claim 7 , wherein the control circuit further comprises a second programmable delay circuit for programming delay of a precharge signal.
9. The memory device of claim 1 , wherein the control circuit further comprises a reset block for programming the sense amplifier enable signal that activates the sense amplifier of the plurality of sense amplifiers when a bit line of the plurality of bit lines and the reference bit line are discharged to a second predefined voltage.
10. The memory device of claim 1 , wherein the memory array comprises at least one of a dynamic random access memory (DRAM), a static random access memory (SRAM) and a read only memory (ROM).