Multi-level signaling in memory with wide system interface
Techniques are provided herein to increase a rate of data transfer across a large number of channels in a memory device using multi-level signaling. Such multi-level signaling may be configured to increase a data transfer rate without increasing the frequency of data transfer and/or a transmit power of the communicated data. An example of multi-level signaling scheme may be pulse amplitude modulation (PAM). Each unique symbol of the multi-level signal may be configured to represent a plurality of bits of data.
1. An apparatus, comprising:
an array of memory cells;
a controller configured to control operation of memory cells in the array of memory cells;
an interposer formed of a first material and operatively coupled with the array of memory cells and the controller, wherein the interposer comprises a plurality of channels between the array of memory cells and the controller;
a substrate coupled with the interposer and formed of a second material different than the first material; and
a receiver configured to determine a logic state represented by a signal modulated using a first modulation scheme communicated across at least one channel of the interposer.
2. The apparatus of claim 1 , further comprising:
a driver configured to generate the signal to be transmitted across the at least one channel of the interposer based at least in part on a plurality of information bits.
3. The apparatus of claim 1 , wherein the signal comprises a binary-level signal.
4. The apparatus of claim 3 , wherein the first modulation scheme comprises a non-return-to-zero (NRZ) scheme, a unipolar encoding scheme, a bipolar encoding scheme, a Manchester encoding scheme, a two-level pulse amplitude modulation (PAM) scheme, or a combination thereof.
5. The apparatus of claim 1 , wherein the signal comprises a non-binary signal.
6. The apparatus of claim 5 , wherein the first modulation scheme comprises a four-level pulse amplitude modulation (PAM) scheme, an eight-level PAM scheme, a quadrature amplitude modulation (QAM) scheme, quadrature phase shift keying, or a combination thereof.
7. The apparatus of claim 1 , wherein the controller transmits the signal across a subset of the plurality of channels of the interposer to the array of memory cells.
8. The apparatus of claim 1 , wherein the controller transmits the signal using a unidirectional channel of the interposer.
9. The apparatus of claim 1 , wherein the array of memory cells transmits the signal across a subset of the plurality of channels of the interposer to the controller.
10. The apparatus of claim 1 , wherein the receiver further comprises:
a plurality of comparators, each comparator configured to compare the signal to a reference voltage.
11. The apparatus of claim 10 , wherein the receiver further comprises:
a decoder configured to determine a plurality of bits represented by the signal based at least in part on information received from a set of the plurality of comparators.
12. The apparatus of claim 11 , wherein the decoder comprises a look-up table that indexes the information received from the set of the plurality of comparators to the plurality of bits represented by the signal.
13. A method, comprising:
identifying, by a controller of a memory device, information to be written to an array of memory cells;
generating, by the controller, a signal that represents a plurality of bits of the identified information, wherein the signal is modulated using a first modulation scheme; and
transmitting, by the controller, the signal to the array of memory cells across an interposer that comprises a plurality of channels, wherein the interposer is formed of a first material and coupled with a substrate formed of a second material different than the first material.
14. The method of claim 13 , further comprising:
comparing, by the array of memory cells, the signal to one or more voltage thresholds.
15. The method of claim 14 , further comprising:
identifying, by the array of memory cells, the plurality of bits represented by the signal based at least in part on comparing the signal to the one or more voltage thresholds; and
writing, by the array of memory cells, the plurality of bits represented by the signal to one or more memory cells of the array of memory cells.
16. The method of claim 13 , wherein the signal comprises a binary-level signal.
17. The method of claim 16 , wherein the first modulation scheme comprises a non-return-to-zero (NRZ) scheme, a unipolar encoding scheme, a bipolar encoding scheme, a Manchester encoding scheme, a two-level pulse amplitude modulation (PAM) scheme, or a combination thereof.
18. The method of claim 13 , wherein the signal comprises a non-binary signal.
19. The method of claim 18 , wherein the first modulation scheme comprises a four-level pulse amplitude modulation (PAM) scheme, an eight-level PAM scheme, a quadrature amplitude modulation (QAM) scheme, quadrature phase shift keying, or a combination thereof.
20. An apparatus, comprising:
an array of memory cells;
an interposer formed of a first material and operatively coupled with the array of memory cells, wherein the interposer comprises a plurality of channels;
a substrate coupled with the interposer and formed of a second material different than the first material; and
a controller operatively coupled with the interposer, the controller configured to:
identify information to be written to the array of memory cells;
generate a signal that represents a plurality of bits of the identified information, wherein the signal is modulated using a first modulation scheme; and
transmit the signal to the array of memory cells across the interposer.