Abstract: A system for improving system cycle time while supporting 1½ cycle data paths with a PLL based clock system using a communication circuit providing a first mode of operation whereby a first cycle time is obtained, and for allowing use of a second mode of operation whereby a second longer multi-mode cycle time is obtained to extend the time for evaluation of data on the bi-directional data path between a first chip and a memory circuit.

Abstract: A memory control device, having a common synchronous interface coupled thereto, for accessing asynchronous memory devices, as well as other synchronous devices. The memory control device receives, via the synchronous interface, a command having a synchronous format, and translates at least a portion of the command from the synchronous format to an asynchronous format. The command in the asynchronous format is then used to access an asynchronous memory device. The asynchronous memory device can have one of various formats, each of which is supported by the memory control device. The memory control device emulates synchronous memory devices for the system memory controller coupled to the memory control device, even when asynchronous devices are accessed. The memory control device can also translate commands from one synchronous format to another synchronous format such that memory devices of the another synchronous format can be accessed.