Controlling a flash device having time-multiplexed, on-die-terminated signaling interface
An IC die transmits command signals, address signals and data signals to a flash memory device at respective times via a time-multiplexed external signaling line, the data signals representing data to be stored within an array of non-volatile storage elements of the flash memory device. The IC die additionally transmits a control signal to the flash memory device via one or more external control signal lines, the control signal directing the flash memory device to switchably couple an on-die termination element to the time-multiplexed signaling line.
1. An integrated circuit (IC) die having a memory controller function to control a flash memory device having an array of non-volatile storage elements and a termination element, the IC die comprising:
a first signaling circuit to transmit to the flash memory device, via a time-multiplexed signaling line external to the IC die, command signals, address signals and data signals at respective times, the data signals representing data to be stored within the array of non-volatile storage elements; and
circuitry to transmit a control signal to the flash memory device via one or more control signal lines external to the IC die, the control signal to direct the flash memory device to switchably couple the termination element to the time-multiplexed signaling line.
2. The IC die of claim 1 wherein the control signal comprises an enable signal.
3. The IC die of claim 1 wherein the flash memory device switchably couples the termination element to the time-multiplexed signaling line at least in part in response to (i) transition of the control signal from a first logic state to a second logic state, and (ii) one or more of the command signals transmitted via the time-multiplexed signaling line.
4. The IC die of claim 1 wherein the control signal comprises a termination control signal to be transmitted via a termination control line.
5. The IC die of claim 1 wherein the first signaling circuit transmits, to the flash memory device, a value that indicates a first resistance to be implemented by the termination element.
6. The IC die of claim 1 wherein the first signaling circuit transmits, to the flash memory device, first and second values that indicate respective first and second resistances to be implemented at different times by the termination element of the flash memory device.
7. The IC die of claim 1 wherein the circuitry to transmit the control signal comprises differential signaling circuitry to transmit the control signal via a differential signaling path having first and second constituent signaling lines.
8. The IC die of claim 1 wherein the first signaling circuit comprises receiver circuitry to receive a data signal via the time-multiplexed signaling line during a data reception interval in which neither command, address nor data signals are being transmitted by the first signaling circuit.
9. The IC die of claim 1 further comprising a circuit to transmit, to the flash memory device, a chip-select signal indicating that the flash memory device is a target for a signaling transaction.
10. The IC die of claim 1 further comprising a circuit to transmit, to the flash memory device, a chip-select signal that enables the flash memory device to respond to a command conveyed, at least in part, by one or more of the command signals transmitted by the first signaling circuit via the time-multiplexed signaling line.
11. The IC die of claim 1 further comprising a second signaling circuit to transmit a timing signal to the flash memory device via a timing signal line external to the IC die.
12. A method of operation within a IC die that controls a flash memory device having an array of non-volatile storage elements and a termination element, the method comprising:
transmitting to the flash memory device, via a time-multiplexed signaling line external to the IC die, command signals, address signals and data signals at respective times, the data signals representing data to be stored within the array of non-volatile storage elements; and
transmitting a control signal to the flash memory device via one or more control signal lines external to the IC die, the control signal directing the flash memory device to switchably couple the termination element to the time-multiplexed signaling line.
13. The method of claim 12 wherein transmitting the control signal comprises transmitting an enable signal.
14. The method of claim 12 wherein transmitting the control signal via one or more control signal lines comprises transmitting a termination control signal via a termination control line.
15. The method of claim 12 wherein transmitting the command signals to the flash memory device comprises transmitting a command that directs the flash memory device to store, within a programmable storage register of the flash memory device, a value that indicates a first resistance to be implemented by the termination element.
16. The method of claim 12 wherein transmitting the command signals to the flash memory device comprises transmitting a command that directs the flash memory device to store, within one or more programmable storage registers of the flash memory device, first and second values that indicate first and second resistances to be implemented at different times by the termination element.
17. The method of claim 12 wherein transmitting the control signal via one or more control lines comprises transmitting a differential control signal via first and second constituent signaling lines of a differential signaling path.
18. The method of claim 12 further comprising receiving a read data signal from the flash memory device via the time-multiplexed signaling line during a data reception interval in which neither command, address nor data signals are being transmitted by the IC die, wherein the flash memory device is to switchably decouple the termination element from the time-multiplexed signaling line while transmitting the read data signal.
19. The method of claim 12 further comprising transmitting a chip-select signal to the flash memory device indicating that the flash memory device is a target for a signaling transaction.
20. A non-transitory machine-readable medium that stores data representative of an IC die comprising:
a first signaling circuit to transmit to a flash memory device, via a time-multiplexed signaling line external to the IC die, command signals, address signals and data signals at respective times, the data signals representing data to be stored within an array of non-volatile storage elements of the flash memory device; and
circuitry to transmit a control signal to the flash memory device via one or more control signal lines external to the IC die, the control signal to direct the flash memory device to switchably couple a termination element of the flash memory device to the time-multiplexed signaling line.