Patent ID: 8166238
Filing Date: 2012-04-24
Classification: G11C

Abstract:
1. A method of performing refresh operation in a memory device having multiple ports, the method comprising: setting a refresh register when an unauthorized refresh command is generated by one of the ports not having access to the memory device; activating an internal refresh signal for performing an internal refresh operation in the memory device at a subsequent transition in port authority if said refresh register has been set; and activating a refresh by command signal such that a command refresh operation is performed in the memory device when an authorized refresh command is generated by one of the ports having access to the memory device; wherein a state of the refresh by command signal is not determined by any information in said refresh register; and wherein the internal refresh signal and the refresh by command signal are separate signals; and wherein said refresh register is set when a first unauthorized refresh command is generated by a first port of said multiple ports not having access to the memory device, and wherein said refresh register is further set when a second unauthorized refresh command is generated by a second port of said multiple ports not having access to the memory device; and wherein said refresh by command signal is activated when the first authorized refresh command is generated by the first port of said multiple ports having access to the memory device, and wherein said refresh by command signal is activated when the second authorized refresh command is generated by the second port of said multiple ports having access to the memory device.