Word line auto-booting in a spin-torque magnetic memory having local source lines

摘要

In a spin-torque magnetic random access memory (MRAM) that includes local source lines, auto-booting of the word line is used to conserve power consumption by reusing charge already present from driving a plurality of bit lines during writing operations. Auto-booting is accomplished by first driving the word line to a first word line voltage. After such driving, the word line isolated. Subsequent driving of the plurality of bit lines that are capacitively coupled to the word line causes the word line voltage to be increased to a level desired to allow sufficient current to flow through a selected memory cell to write information into the selected memory cell. Additional embodiments include the use of a supplemental voltage provider that is able to further boost or hold the isolated word line at the needed voltage level.

主权项

1. A memory, comprising:
a first source line; a first set of memory cells; a first plurality of bit lines; a first set of selection transistors, wherein each selection transistor of the first set of selection transistors is coupled in series with a corresponding memory cell of the first set of memory cells, wherein each selection transistor and corresponding memory cell are coupled in series between the first source line and a corresponding bit line of the first plurality of bit lines; a word line coupled to a gate of each selection transistor of the first set of selection transistors; a word line driver coupled to the word line, wherein the word line driver is configured to drive the word line to a word line voltage; circuitry coupled to the word line, wherein the circuitry is configured to isolate the word line from the word line driver after the word line is driven to the word line voltage, wherein isolating the word line produces an isolated word line; and first driver circuitry coupled to the first plurality of bit lines, the first driver circuitry configured to drive each bit line of the first plurality of bit lines to a first bit line voltage, wherein the first bit line voltage is different than the first word line voltage, and wherein driving each bit line of the first plurality of bit lines to the first bit line voltage adjusts voltage on the isolated word line to a second word line voltage.