Individually addressing memory devices disconnected from a data bus
Memory devices and methods for operating the same are provided. A memory device can include at least one command contact and at least one data contact. The memory device can be configured to detect a condition in which the at least one command contact is connected to a controller and the at least one data contact is disconnected from the controller, and to enter, based at least in part on detecting the condition, a first operating mode with a lower nominal power rating than a second operating mode. Memory modules including one or more such memory devices can be provided, and memory systems including controllers and such memory modules can also be provided.
1. A memory module, comprising:
a plurality of memories, each of the plurality of memories including:
at least one command contact, and
at least one data contact,
wherein at least one of the plurality of memories is configured to:
detect a condition in which the at least one command contact thereof is connected to a controller and the at least one data contact thereof is disconnected from the controller, and
enter, based at least in part on detecting the condition, a reduced-power mode.
2. The memory module of claim 1 , further comprising:
a connector including:
a plurality of connector data contacts, each of the plurality of connector contacts coupled to a corresponding one of the at least one data contacts of one of the plurality of memories, and
a plurality of connector command contacts, each of the plurality of connector command contacts coupled to a corresponding one or more of the at least one command contacts of the plurality of memories.
3. The memory module of claim 1 , wherein the at least one command contact of each of the plurality of memories is coupled to a common command/address bus.
4. The memory module of claim 1 , wherein the at least one of the plurality of memories is configured to detect the condition by detecting a command signal at the at least one command contact and determining that the at least one data contact is grounded.
5. The memory module of claim 4 , wherein the command signal comprises a reset signal.
6. The memory module of claim 1 , wherein the at least one command contact of each of the plurality of memories includes a first strobe contact and a second strobe contact, and wherein the at least one of the plurality of memories is configured to detect the condition based at least in part on determining that the first and second strobe contacts are driven to opposing high and low levels.
7. The memory module of claim 6 , wherein the first strobe contact and the second strobe contact are coupled to a first-in first-out (FIFO) counter, and wherein determining that the first and second strobe contacts are driven to opposing high and low levels includes determining that the FIFO counter is below a predetermined threshold.
8. The memory module of claim 1 , wherein the reduced-power mode is a mode in which the at least one of the plurality of memories is configured to ignore signals received at the at least one command contact.
9. The memory module of claim 1 , wherein the condition is a first condition, and wherein the at least one of the plurality of memories is configured to exit the reduced-power mode based at least in part upon detecting a second condition in which the data contact is connected to the controller.
10. A method of operating a memory module having a plurality of memories, comprising:
detecting a condition in which at least one command contact of at least one memory of the plurality of memories is connected to a controller and at least one data contact of the at least one memory is disconnected from the controller; and
entering, based at least in part on detecting the condition, a reduced-power mode.
11. The method according to claim 10 , wherein detecting the condition includes detecting a command signal at the at least one command contact and determining that the at least one data contact is grounded.
12. The method of claim 11 , wherein the command signal comprises a reset signal.
13. The method of claim 10 , wherein the at least one command contact includes a first strobe contact and a second strobe contact, and wherein detecting the condition includes determining that the first and second strobe contacts are driven to opposing high and low levels.
14. The method of claim 13 , wherein the first strobe contact and the second strobe contact are coupled to a first-in first-out (FIFO) counter, and wherein determining that the first and second strobe contacts are driven to opposing high and low levels includes determining that the FIFO counter is below a predetermined threshold.
15. The method of claim 10 , further comprising ignoring signals received at the at least one command contact while the at least one memory is in the reduced-power mode.
16. The method of claim 10 , wherein the condition is a first condition, and further comprising:
detecting a second condition in which the data contact is connected to the controller; and
based at least in part on detecting the second condition, exiting the reduced-power mode.