Memory system capable of performing a bit partitioning process and an internal computation process
A memory system includes a plurality of first memory units, a plurality of read word lines, and a plurality of read bit lines. Each first memory unit of the plurality of first memory units includes a second memory unit, a first transistor coupled to the second memory unit, and a second transistor coupled to the second memory unit and the first transistor. Each read word line of the plurality of read word lines is coupled to a plurality of first transistors disposed along a corresponding row. Each read bit line of the plurality of read bit lines is coupled to a plurality of second transistors disposed along a corresponding column.
1. A memory system comprising:
a plurality of first memory units, each first memory unit of the plurality of first memory units comprising:
a second memory unit;
a first transistor coupled to the second memory unit; and
a second transistor coupled to the second memory unit and the first transistor;
a plurality of read word lines, each read word line of the plurality of read word lines being coupled to a plurality of first transistors disposed along a corresponding row; and
a plurality of read bit lines, each read bit line of the plurality of read bit lines being coupled to a plurality of second transistors disposed along a corresponding column;
wherein a current of the each read bit line is generated by performing a linear combination on a plurality of currents of the plurality of read word lines.
2. The system of claim 1 , further comprising:
an input register array configured to receive a plurality of input data vectors;
a plurality of multiplexers coupled to the input register array and the plurality of read word lines, each multiplexer of the plurality of multiplexers being configured to generate a multiplexer output signal according to the plurality of input data vectors; and
a control signal generator coupled to the plurality of multiplexers and configured to generate a plurality of control signals for controlling the plurality of multiplexers.
3. The system of claim 1 , wherein the second memory unit comprises:
a third transistor comprising:
a first terminal coupled to a first bit line;
a second terminal; and
a control terminal;
a fourth transistor comprising:
a first terminal;
a second terminal coupled to a second bit line; and
a control terminal coupled to the control terminal of the third transistor;
a first inverter comprising:
an input terminal coupled to the second terminal of the third transistor; and
an output terminal coupled to the first terminal of the fourth transistor and a control terminal of the second transistor; and
a second inverter comprising:
an input terminal coupled to the output terminal of the first inverter; and
an output terminal coupled to the input terminal of the first inverter and a first terminal of the first transistor;
wherein a second terminal of the first transistor is coupled to a first terminal of the second transistor, a control terminal of the first transistor is coupled to a read word line of the plurality of read word lines, a second terminal of the second transistor is coupled to a read bit line of the plurality of read bit lines, and two signals of the first bit line and the second bit line are complementary.
4. The system of claim 3 , wherein when the input terminal of the first inverter is at a high voltage, the input terminal of the second inverter is at a low voltage, and the first transistor and the second transistor are enabled for outputting a current to the read bit line.
5. The system of claim 3 , wherein when the input terminal of the first inverter is at a low voltage, the input terminal of the second inverter is at a high voltage, and the second transistor is disabled so that a current of the read bit line is blocked.
6. The system of claim 1 , wherein the first transistor is an N-type metal-oxide-semiconductor field-effect transistor, and the second transistor is a P-type metal-oxide-semiconductor field-effect transistor.
7. The system of claim 1 , further comprising:
a plurality of voltage-to-time converters coupled to the plurality of read bit lines and configured to generate a plurality of output signals in a time domain;
a plurality of analog-to-digital(A/D) converters, each A/D converter of the plurality of A/D converters being coupled to a corresponding voltage-to-time converter for outputting a digital signal; and
an output synthesizer coupled to the plurality of A/D converters and configured to generate an output signal;
wherein a dimension of the each A/D converter is NADC, and NADC is a positive integer.
8. The system of claim 7 , wherein the each A/D converter quantizes the output signal of the each read bit line in a time domain into a digital signal with 2 NADC levels, and the number of A/D converters is smaller than or equal to a column dimension of the plurality of first memory units.
9. The system of claim 7 , wherein the output synthesizer sums up sequentially shifted digital signals generated by the plurality of A/D converters for generating the output signal.
10. The system of claim 7 , wherein the plurality of A/D converters are a plurality of time-to-digital converters for converting the plurality of output signals in a time domain generated by the voltage-to-time converters into the plurality of digital signals, and sampling accuracy of the voltage-to-time converters increases with improvement of manufacturing process of the voltage-to-time converters.