On-die termination control
A memory control component outputs a memory write command to a memory IC and also outputs write data to be received via data inputs of the memory IC. Prior to reception of the write data within the memory IC, the memory control component asserts a termination control signal that causes the memory IC to apply to the data inputs a first on-die termination impedance during reception of the write data followed by a second on-die termination impedance after the write data has been received. The memory control component deasserts the termination control signal to cause the memory IC to apply no termination impedance to the data inputs.
1. An integrated circuit device comprising:
a first signaling interface to be coupled to a dynamic random access memory component (DRAM), the DRAM having a first register to store a first control value and a second register to store a second control value; and
control circuitry to transmit to the DRAM via the first signaling interface one or more commands that instruct the DRAM to:
store the first control value within the first register of the DRAM, the first control value specifying a first termination to be applied to a data interface of the DRAM during a write-data reception interval in which write data is received by the DRAM via the data interface; and
store the second control value within the second register of the DRAM, the second control value specifying a second termination that is to be applied to the data interface after the write-data reception interval transpires.
2. The integrated circuit device of claim 1 wherein the control circuitry is further to transmit to the DRAM via the first signaling interface a write command to be received by the DRAM a predetermined time prior to the write-data reception interval.
3. The integrated circuit device of claim 2 wherein the control circuitry to transmit the write command to the DRAM comprises circuitry to cause the DRAM, by transmission of the write command and reception thereof within the DRAM, to apply the first termination to the data interface of the DRAM during the write data reception interval and to apply the second termination to the data interface of the DRAM after the write-data reception interval transpires.
4. The integrated circuit device of claim 1 wherein the first signaling interface comprises a plurality of command/address signal transmitters and a plurality of data signal transceivers and wherein the control circuitry is further to transmit the write data to the DRAM via the plurality of data signal transceivers such that the write data arrives at the data interface of the DRAM during the write-data reception interval.
5. The integrated circuit device of 4 further comprising a second signaling interface comprising a plurality of command/address signal receivers to receive commands from a memory controller and a plurality of data signal transceivers to output data signals to and receive data signals from the memory controller.
6. The integrated circuit device of claim 4 wherein the control circuitry to transmit the one or more commands to the DRAM via the first signaling interface comprises circuitry to transmit the one or more commands to the DRAM via the command/address signal transmitters.
7. The integrated circuit device of claim 1 wherein the control circuitry to transmit the one or more commands to the DRAM via the first signaling interface additionally transmits the one or more control values to the DRAM via the first signaling interface.
8. The integrated circuit device of claim 7 wherein the control circuitry to transmit the first and second control values to the DRAM comprises circuitry to transmit, via the first signaling interface, a first digital value that corresponds to the first termination and a second digital value that corresponds to the second termination.
9. The integrated circuit device of claim 8 wherein the first digital value comprises a first bit pattern indicative of an impedance of the first termination, and the second digital value comprises a second bit pattern indicative of an impedance of the second termination, wherein the first bit pattern and the second bit pattern are different.
10. The integrated circuit device of claim 1 wherein the first and second terminations comprise first and second impedance values, the first impedance value being higher than the second impedance value.
11. A method of operation within an integrated circuit device, the method comprising:
transmitting, to a dynamic random access memory component (DRAM) via a first signaling interface, one or more commands that instruct the DRAM to:
store a first control value within a first register of the DRAM, the first control value specifying a first termination to be applied to a data interface of the DRAM during a write-data reception interval in which write data is received by the DRAM via the data interface; and
store a second control value within a second register of the DRAM, the second control value specifying a second termination that is to be applied to the data interface after the write-data reception interval transpires; and
transmitting to the DRAM via the first signaling interface a write command indicating that the write data is to be received within the DRAM component.
12. The method of claim 11 further comprising transmitting the write data to the DRAM via the first signaling interface.
13. The method of claim 11 wherein transmitting the write command to the DRAM comprises causing the DRAM to apply the first termination to the data interface of the DRAM during the write data reception interval and to apply the second termination to the data interface of the DRAM after the write-data reception interval transpires.
14. The method of claim 11 wherein the first signaling interface comprises a plurality of command/address signal transmitters and a plurality of data signal transceivers, the method further comprising transmitting the write data to the DRAM via the plurality of data signal transceivers such that the write data arrives at the data interface of the DRAM during the write-data reception interval.
15. The method of 14 further receiving commands from a memory controller via a second signaling interface and outputting data signals to and receiving data signals from the memory controller via the second signaling interface.
16. The method of claim 14 wherein transmitting the one or more commands that instruct the DRAM to store the first and second control values comprises transmitting the one or more commands to the DRAM via the command/address signal transmitters.
17. The method of claim 11 further comprising transmitting the first and second control values to the DRAM via the first signaling interface.
18. The method of claim 17 wherein transmitting the first and second control values to the DRAM comprises transmitting, via the first signaling interface, a first digital value that corresponds to the first termination and a second digital value that corresponds to the second termination.
19. The method of claim 18 wherein the first digital value comprises a first bit pattern indicative of an impedance of the first termination, and the second digital value comprises a second bit pattern indicative of an impedance of the second termination, the impedance of the first termination being higher than the impedance of the second termination.
20. An integrated circuit device comprising:
a first signaling interface to be coupled to a dynamic random access memory component (DRAM); and
means for transmitting to the DRAM via the first signaling interface one or more commands that instruct the DRAM to:
store a first control value within a first register of the DRAM, the first control value specifying a first termination to be applied to a data interface of the DRAM during a write-data reception interval in which write data is received by the DRAM via the data interface; and
store a second control value within a second register of the DRAM, the second control value specifying a second termination that is to be applied to the data interface after the write-data reception interval transpires.