Unsuccessful write retry buffer
A memory module includes at least two memory devices. Each of the memory devices perform verify operations after attempted writes to their respective memory cores. When a write is unsuccessful, each memory device stores information about the unsuccessful write in an internal write retry buffer. The write operations may have only been unsuccessful for one memory device and not any other memory devices on the memory module. When the memory module is instructed, both memory devices on the memory module can retry the unsuccessful memory write operations concurrently. Both devices can retry these write operations concurrently even though the unsuccessful memory write operations were to different addresses.
1. A method of operating a memory controller, comprising:
receiving an indicator of a condition of a retry buffer of a first memory device, the retry buffer of the first device storing write information associated with verify operations performed by the first memory device that have determined corresponding write operations by the first memory device have failed in a manner that causes loss of data; and,
in response to the indicator, sending a command to the first memory device to retry at least one unsuccessful write operation associated with an entry in the retry buffer of the first memory device.
2. The method of claim 1 , further comprising:
in response to the indicator, send the command to a second memory device to retry at least one unsuccessful write operation associated with an entry in the retry buffer of the second memory device, the retry buffer of the second device storing write information associated with verify operations performed by the second memory device that have determined corresponding write operations by the second memory device have failed in a manner that causes loss of data.
3. The method of claim 1 , further comprising:
in response to the indicator, stop scheduling write operations to be sent to the first memory device.
4. The method of claim 1 , further comprising:
in response to the indicator, stop scheduling write operations to be sent to a bank of the first memory device.
5. The method of claim 1 , wherein in response to the command, the first memory device reads the entry in the retry buffer of the first memory device to retry the at least one unsuccessful write operation.
6. The method of claim 1 , wherein in response to a read command, the first memory device reads the entry in the retry buffer of the first memory device to respond to the read command.
7. A memory controller, comprising:
a first interface to transmit a first command to a first memory device, the first command to cause the first memory device to perform a first verify operation that determines the first command was unsuccessful in a manner that causes loss of data and to store a first entry in a first internal write retry buffer; and
a scheduler to schedule a second command to the first memory device to cause the first memory device to retry the first command using information stored in the first entry.
8. The memory controller of claim 7 , further comprising:
a second interface to receive an indicator that the first internal write retry buffer meets a threshold criteria associated with a number of used entries in the first internal write retry buffer.
9. The memory controller of claim 8 , wherein the scheduler is to schedule the second command based at least in part on the indicator.
10. The memory controller of claim 9 , wherein the first command is to be concurrently sent to a second memory device on a module with the first memory device.
11. The memory controller of claim 10 wherein the second memory device comprises a second internal write retry buffer.
12. The memory controller of claim 11 , wherein the second interface comprises a flag interface.
13. The memory controller of claim 11 , wherein the second interface comprises a data interface.