Dynamically changing data access bandwidth by selectively enabling and disabling data links

摘要

Bandwidth for information transfers between devices is dynamically changed to accommodate transitions between power modes employed in a system. The bandwidth is changed by selectively enabling and disabling individual control links and data links that carry the information. During a highest bandwidth mode for the system, all of the data and control links are enabled to provide maximum information throughout. During one or more lower bandwidth modes for the system, at least one data link and/or at least one control link is disabled to reduce the power consumption of the devices. At least one data link and at least one control link remain enabled during each low bandwidth mode. For these links, the same signaling rate is used for both bandwidth modes to reduce latency that would otherwise be caused by changing signaling rates. Also, calibration information is generated for disabled links so that these links may be quickly brought back into service.

主权项

1. A first integrated circuit device that is switchable between operating in at least a first bandwidth mode and operating in a second bandwidth mode, wherein data is transferred between the first integrated circuit device and a second integrated circuit device over a signaling channel comprising a plurality of links at a lower bandwidth while the first integrated circuit is operating in the second bandwidth mode than while the first integrated circuit is operating in the first bandwidth mode, the first integrated circuit device comprising:
a data interface circuit to transfer data while the first integrated circuit is operating in the first bandwidth mode via each link of the plurality of links, and to disable each link of a first subset of the plurality of links while the first integrated circuit is operating in the second bandwidth mode, and to transfer data while the first integrated circuit is operating in the second bandwidth mode via each link of a second subset of the plurality of links that is not disabled, wherein a common signaling rate is employed for the data transfers via the second subset of the plurality of links while the first integrated circuit is operating in the first bandwidth mode and while the first integrated circuit is operating in the second bandwidth mode; and a control interface circuit to transfer control information between the first integrated circuit device and the second integrated circuit device, wherein the control information provides an indication of transitions between the first bandwidth mode and the second bandwidth mode.