Great find Flip,
AmbiqMicro have US9779788:
"
Non-volatile semiconductor memory systems having multiple power states are described. More specifically, components and methods for improving utilization and reducing power requirements of flash memory systems that include sub- or near-threshold components are described."
They say that this is ultra-low power and suitable for battery powered (edge) devices. Hence, I guess, Anil's interest.
The claims are very broad, so they have a strong hold on the claimed technique.
"
1. A non-volatile memory system comprising:a memory array with read circuitry;
a reference cell connected to the read circuitry; and
a voltage reference facility connected to the reference cell and having a sub-threshold reference circuit adapted to operate in a sub-threshold voltage domain.
2. A non-volatile memory system comprising:
a memory array with read circuitry;
a reference cell connected to the read circuitry; and
a voltage reference and bias generating facility connected to the reference cell, the voltage reference and bias generating facility having a both a sub-threshold reference circuit and a bias generating circuit, with the sub-threshold reference circuit switchable to an active state while the bias generating circuit is maintained in a stand-by state.
3. A non-volatile memory system comprising:
a memory array with read circuitry;
a reference cell connected to the read circuitry; and
a voltage reference and bias generating facility connected to the reference cell, the voltage reference and bias generating facility switchable between first mode with a sub-threshold reference circuit active and a second mode with a band-gap reference circuit active.
4. A non-volatile memory system comprising:
a memory array with read circuitry;
a reference cell connected to the read circuitry; and
a voltage reference and bias generating facility connected to the reference cell, the voltage reference and bias generating facility having a both a sub-threshold reference circuit and a bias generating circuit, with the sub-threshold reference circuit switchable to an active state while the bias generating circuit is maintained in a stand-by state.
5. A non-volatile memory system comprising:
a memory array with read circuitry having a read cycle time;
a reference cell connected to the read circuitry; and
a voltage reference and bias generating facility connected to the reference cell, the voltage reference and bias generating facility having a both a sub-threshold reference circuit and a bias generating circuit;
wherein the voltage reference and bias generating facility can be switched from a light-sleep mode to an active mode in a period comprising less than 10 read cycle times.
...
"
Now the interesting thing is that their system uses GPU, yet they still claim ultra-low power although the claims relate to memory.
So I suppose the GPU is asleep until needed.
They have several other patents/applications which I have not looked at yet.
(20min delay)