Integrated circuit device and signaling method with phase control based on information in external memory device
An integrated circuit device includes a transmitting means for transmitting transmit data to an external signal line and a storing means for storing a first value representative of a transmit phase adjustment that is used to adjust when the transmit data is transmitted by the transmitting means. The first value is determined based on information stored in a memory device external to the integrated circuit device.
1. An integrated circuit device, comprising:
a transmitting means for transmitting transmit data to an external signal line; and
a storing means for storing a first value representative of a transmit phase adjustment that is used to adjust when the transmit data is transmitted by the transmitting means;
wherein the first value is determined based on information stored in a memory device external to the integrated circuit device.
2. The integrated circuit device of claim 1 , wherein
the transmitting means transmits data to the external signal line synchronously with respect to an external clock;
the first value is used to adjust when the transmit data is transmitted by the transmitting means relative to the external clock; and
the first value is based on information specifying a configuration of a plurality of integrated circuit devices connected to the external signal line.
3. The integrated circuit device of claim 1 , wherein the integrated circuit device is a first integrated circuit device, the transmit data is transmitted from the first integrated circuit device at a transmit time to a second integrated circuit device, and the transmit phase adjustment is applied to the transmit time such that receive data is sampled substantially centered within a data eye of the receive data by the second integrated circuit device; and
wherein the first value is determined by polling a supplemental memory device that stores information pertaining to the second integrated circuit device.
4. The integrated circuit device of claim 1 , wherein the transmitting means is a circuit to transmit data in response to an internal transmit signal; and
the storing means is a first register to store a first value representative of a transmit phase adjustment that is applied to the internal transmit signal.
5. The integrated circuit device of claim 1 ,
wherein the integrated circuit device communicates with a plurality of other integrated circuit devices, the transmitting means is a transmitter circuit and the storing means is a first register; and
wherein the first value is determined based on information specifying a configuration of the plurality of other integrated circuit devices.
6. The integrated circuit device of claim 5 , wherein the transmit data is transmitted in response to an internal transmit signal, wherein the internal transmit signal is adjusted, based on the first value, to adjust when the data is transmitted.
7. The integrated circuit device of claim 6 , further including a locked loop circuit to generate the internal transmit signal.
8. The integrated circuit device of claim 6 , wherein the first value is selected such that the transmit data is transmitted to substantially center a data eye of receive data with respect to the internal receive signal at a receiving device of the plurality of other integrated circuit devices.
9. The integrated circuit device of claim 5 , wherein the information specifying the configuration of the plurality of other integrated circuit devices is stored in a supplemental memory device, wherein the first value is determined by accessing the supplemental memory device.
10. The integrated circuit device of claim 9 , wherein the supplemental memory device is a serial presence detect memory device.
11. The integrated circuit device of claim 10 , wherein the serial presence detect memory device is associated with a memory module, wherein at least a subset of the plurality of other integrated circuit devices are memory devices disposed on the memory module.
12. The integrated circuit device of claim 5 , further including:
a receiver circuit to sample receive data in response to an internal receive signal; and
a second register to store a second value representative of a receive time adjustment that is applied to the internal receive signal.
13. The integrated circuit device of claim 12 , further including a third register to store a third value representative of a reference voltage level adjustment that is applied to a reference voltage to derive a modified reference voltage level, wherein the receiver circuit samples the receive data using the modified voltage reference level.
14. The integrated circuit device of claim 5 , further including an additional register to store a value representative of a drive strength adjustment that is applied to the transmitter circuit.
15. The integrated circuit device of claim 5 , further including an additional register to store a value representative of a slew rate adjustment that is applied to the transmitter circuit.
16. A method of operation of an integrated circuit device that communicates with a plurality of other integrated circuit devices, the integrated circuit device and the plurality of other integrated circuit devices defining a system, the method comprising:
initializing the system;
storing a first value representative of a transmit phase time adjustment that is applied to an internal transmit signal, wherein the first value is determined based on information stored in a memory device external to the integrated circuit device; and
transmitting transmit data onto an external signal line in response to the internal transmit signal.
17. The method of claim 16 , wherein the method includes transmitting the transmit data onto an external signal line synchronously with respect to an external clock; and
wherein the first value is representative of a transmit phase time adjustment relative to the external clock.
18. The method of claim 16 , further including generating the internal transmit signal using a locked loop circuit.
19. The method of claim 16 , further including storing a second value representative of a slew rate adjustment that is applied to the transmitter circuit.
20. The method of claim 16 , further including accessing the information specifying the configuration of the plurality of other integrated circuit memory devices from a supplemental memory device.
21. The method of claim 20 , wherein the supplemental memory device is a serial presence detect memory device, wherein the serial presence detect memory device is associated with a memory module and at least a subset of the plurality of other integrated circuit devices are memory devices disposed on the memory module.
22. The method of claim 20 , including:
generating the internal transmit signal, using a locked loop circuit, based on an external clock signal;
applying the transmit phase adjustment to the internal transmit signal such that a time at which the transmit data is transmitted is adjusted to substantially center a data eye of receive data with respect to a sample time of another integrated circuit device that receives the transmit data; and
storing the first value in a first register during initialization of the integrated circuit device.
23. The method of claim 22 wherein the locked loop circuit is selected from a phase locked loop circuit and a delay locked loop circuit.
24. The method of claim 16 , including storing, in a register of the integrated circuit device, a value that is representative of a slew rate adjustment that is applied to the transmit data.
25. The method of claim 16 , including
sampling receive data using a receiver circuit of the integrated circuit device; and
storing, in an additional register of the integrated circuit device, a value representative of a parameter adjustment that is applied to the receiver circuit.