Adaptive communication interface
Embodiments of the disclosed subject matter include a communication interface and protocol for allowing communication between devices, circuits, integrated circuits, and other electronic components having, for example, different communication capacities or clock domains. The interface supports communication between any components having any difference in capacity and over any distance. The interface utilizes request and acknowledge phases and signals and an initiator-target relationship between components that allow each side to throttle the communication rate to an accepted level for each component or achieve a desired bit error rate. Other devices, methods, and interfaces are disclosed.
1. A method, comprising:
generating, from a first device having a first communication capacity, a request signal on a first line for initiating a transfer of data;
receiving, by a second device having a second communication capacity, the request signal, the first communication capacity and the second communication capacity being different from one another,
sending, from the second device, an acknowledge signal on a second line;
receiving, at the first device, the acknowledgment signal from the second device; and
delaying propagation of the acknowledgment signal based on a time required for the acknowledgment signal to settle to a new state based on at least one of skew and distortion on the second line to throttle a communication rate of a transfer of data.
2. The method of claim 1 , further comprising:
generating a training sequencing at the first device; and
transmitting the training sequence to the second device.
3. The method of claim 2 , further comprising:
receiving the training sequence at the second device; and
determining a delay time for generating an acknowledgment signal based on a comparison of the training sequence with a known value.
4. The method of claim 1 , further comprising delaying an incoming signal based on time to compensate for skew and distortions over the communication medium.
5. The method of claim 1 , wherein the request signal and the acknowledge signal are non return-to-zero signals.
6. The method of claim 1 , wherein data are transferred during a request phase from the first device to the second device.
7. The method of claim 1 , wherein data are transferred from the second device to the first device during an acknowledgement phase.
8. The method of claim 1 , further comprising managing communications between devices by throttling a communication speed over the communication medium without exceeding a predetermined bit error rate.
9. The method of claim 1 , wherein the first line is a dedicated request line for transmitting the request signal for initiating a transfer of data between the first device and the second device.
10. The method of claim 1 , wherein the second line is a dedicated acknowledge line for transmitting the acknowledge signal.
11. The method of claim 1 , wherein a difference between the delay of the first delayed version of the acknowledge signal and a delay of a second delayed version of the acknowledge signal is equal to a minimum pulse width to strobe a storage device for reading or writing data.
12. A system, comprising:
an initiator device having a first communication capacity to couple to a communication medium and to generate a request signal to initiate a transfer of data; and
a target device having a second communication capacity to receive the request signal from the initiator device and to generate an acknowledgement signal, the first communication capacity and the second communication capacity being different from one another, the acknowledgment signal to be delayed by the initiator device based on a time required for the acknowledgment signal to settle to a new state based on at least one of skew and distortion of the received acknowledgment signal in order to throttle a communication rate of the data.
13. The system of claim 12 , further comprising a sequence generator to transmit a data sequence to be used to determine a delay time necessary to achieve a desired error bit rate.
14. The system of claim 12 , further comprising a correlator to receive a known data sequence and determine a delay time necessary to achieve a desired error bit rate.
15. The system of claim 12 , wherein the initiator device and target device have different rate transfer capacities.
16. The system of claim 12 , wherein the initiator device is situated within a central processing unit of the system and the target device is situated within a chipset of the system.
17. A method, comprising:
generating a request signal;
sending an acknowledgment signal in response to the request signal; and
delaying propagation of the acknowledgment signal based on a time required for the acknowledgment signal to settle to a new state based on at least one of skew and distortion of the received acknowledgment signal to throttle a communication rate of a transfer of data, wherein the throttling of the communication rate of the transfer of data includes setting a communication rate based on the time required for the acknowledgment signal to settle to a new state, and ending a data read or a data write in response to a second delayed version of the acknowledgment signal, a difference between the delayed propagation of the acknowledgment signal and a delay of the second delayed version of the acknowledgement signal being equal to a minimum pulse width to strobe a storage device for the data read or the data write.
18. The method of claim 17 , wherein throttling the commination rate of the transfer of data comprises:
initiating a read or write in response to the delayed propagation of the acknowledgment signal; and
ending the data read or the data write in response to a second delayed version of the acknowledgment signal.