Advanced memory interfaces and methods
Controllers, interfaces, memory devices, methods and systems are disclosed, including a controller configured to interface with a separate memory device and perform an iterative write operation to program a selected memory cell of the memory device to a target state, wherein each iteration of the write operation is configured to successively change a physical state of the selected memory cell. Other controllers, interfaces, memory device, methods and systems are also described, such as those where either a controller or a memory device can throttle a data communication operation, and/or those that utilize customized programming pulses.
1. An interface for use in a system that includes a controller and a memory device, the interface comprising:
a synchronous handshake line configured for bidirectional signaling between the controller and the memory device, wherein the controller and the memory device are each configured to control data communication over the interface by signaling on the synchronous handshake line and the controller is configured to initiate a current operation using the synchronous handshake line by (i) driving the synchronous handshake line to an active state from an inactive state to initiate the current operation, (ii) recognizing the inactive state on the synchronous handshake line as a prerequisite to driving the synchronous handshake line to the active state to initiate the current operation (iii) releasing the synchronous handshake line from the active state after a particular interval that is sufficient in duration for the memory device to recognize the active state, (iv) recognizing the active state during the particular interval, and (v) maintaining the synchronous handshake line in the active state responsive to recognizing the active state during the particular interval.
2. The interface of claim 1 , wherein the synchronous handshake line is configured to interface a handshake section of the controller with a handshake section of the memory device.
3. The interface of claim 1 further comprising a serial clock line and a bidirectional serial data line, wherein the serial clock line and the serial data line are configured to interface a serial processor section of the controller with a serial communication section of the memory device, wherein the serial processor section and the serial communication section are configured to cooperatively control addressing, command and control functions over the serial clock line and the bidirectional serial data line.
4. The interface of claim 1 , wherein the synchronous handshake line comprises a bidirectional synchronous handshake line.
5. The interface of claim 1 wherein each of the controller and the memory device are configured to throttle the data communication via the synchronous handshake line by inducing a wait condition on the interface to pause a current operation.
6. The interface of claim 1 wherein each of the controller and the memory device maintain the wait condition via the synchronous handshake line until each of the controller and the memory device are in a ready state with respect to the current operation.
7. The interface of claim 1 wherein the memory device is configured to maintain the active state for another particular time interval and to drive the synchronous handshake line to the inactive state responsive to termination of the particular time interval.
8. The interface of claim 1 wherein the bidirectional synchronous handshake line includes no more than a single electrical conductor.
9. In a memory system including a controller that is interfaced with a memory device by an interface including a handshake line, a method comprising:
synchronously bidirectionally signaling from each of the controller and the memory device over the handshake line to control data communication over the interface by driving the handshake line with the controller to an active state to initiate a read operation in the memory device such that the controller releases the handshake line after driving the handshake line for a particular interval that is sufficient in duration for the memory device to recognize the active state and maintaining the handshake line in the active state with the memory device responsive to determining that the handshake line has been driven to the active state; and
controlling the data communication responsive to the signaling.
10. The method of claim 9 , wherein controlling the data communication comprises controlling serial to parallel converters in the memory device responsive to the signaling.
11. The method of claim 10 further comprising said synchronously signaling on no more than a single electrical conductor.
12. The method of claim 9 , wherein controlling the data communication comprises controlling digital to analog converters in the memory device responsive to the signaling.
13. The method of claim 9 , wherein the memory device drives the handshake line inactive after another particular interval.
14. The method of claim 13 , wherein sample and hold circuitry in the controller latch read data over the interface responsive to the memory device driving the handshake line inactive.
15. The method of claim 13 , wherein the memory device provides digital data over the interface responsive to the controller driving the handshake line active.
16. The method of claim 15 , wherein the memory device drives the handshake line inactive responsive to providing the digital data.
17. The method of claim 9 , further comprising issuing a command over the interface, where a clear iterate pulse in the command indicates that an operation specified by the command is an initial write operation and is not an iteration of an iterative write operation.
18. The method of claim 9 , wherein controlling the data communication comprises controlling an arrangement of analog to digital converters in the memory device responsive to the signaling.
19. In a memory system including a controller that is interfaced with a memory device by an interface including a handshake line, a method comprising:
synchronously bidirectionally signaling from each of the controller and the memory device over the handshake line to control data communication over the interface by driving the handshake line with the controller to an active state to initiate a write operation in the memory device, wherein the controller releases the handshake line after driving the handshake line for a particular interval that is sufficient in duration for the memory device to recognize the active state and the memory device maintains the handshake line in the active state responsive to determining that the handshake line has been driven to the active state; and
controlling the data communication responsive to the signaling.
20. The method of claim 19 , wherein the memory device drives the handshake line inactive responsive to the memory device being ready for the write operation.
21. The method of claim 20 , wherein signaling over the handshake line further comprises driving the handshake line active again to initiate a read back operation in the memory device, wherein the handshake line is driven inactive again by the memory device responsive to read data being stabilized for communication to the controller.
22. The method of claim 21 , wherein the controller latches the read data responsive to the handshake line being driven inactive again by the memory device.
23. The method of claim 20 , wherein the controller provides write data over the interface responsive to the memory device driving the handshake line inactive.
24. The method of claim 23 , wherein signaling over the handshake line further comprises driving the handshake line active again responsive to the write data being present in serial to parallel converters of the memory device.
25. The method of claim 24 , wherein the memory device drives the handshake line inactive again responsive to completing the write operation, and the controller initiates a read back operation responsive to the memory device driving the handshake line inactive again.
26. In a memory system including a controller that is interfaced with a memory device by an interface including a handshake line, a method comprising:
synchronously bidirectionally signaling from each of the controller and the memory device over the handshake line to control data communication over the interface by driving the handshake line with the controller to an active state to initiate a write operation in the memory device wherein pulse unit analog to digital converters in the controller convert write data to analog data responsive to the controller driving the handshake line active and the controller releases the handshake line after driving the handshake line a particular interval and the memory device drives the handshake line inactive responsive to the memory device being ready for the write operation; and
controlling the data communication responsive to the signaling.
27. The method of claim 26 , wherein the controller provides the analog data over the interface responsive to the memory device driving the handshake line inactive.