Patent ID: 7203870
Filing Date: 2007-04-10
Classification: G11C

Abstract:
1. A semiconductor memory unit with a repair circuit that compares a read/write target memory address with a repair target memory address, and activates, when the two addresses agree with each other, a corresponding repair memory instead of a corresponding read/write target memory, said semiconductor memory unit with a repair circuit comprising: at least one repair address memory for storing the repair target memory address; a shared address decoder for decoding a read/write target memory address signal supplied from outside, and repair target memory address signal output from said repair address memory; a selector for selecting one of the read/write target memory address signal and the repair target memory address signal to be supplied to said shared address decoder; an address comparator that includes a repair signal information holding section for holding the repair target memory address decoded by said shared address decoder, and compares the repair target memory address with the read/write target memory address decoded by said shared address decoder; and a controller for supplying said selector and said address comparator with a control signal, wherein when said selector is controlled to supply said shared address decoder with the repair target memory address signal by said control signal, said address comparator is controlled to have said repair signal information holding section hold the repair target memory address in response to the control signal, and wherein when said selector is controlled to supply said shared address decoder with the read/write target memory address signal by said control signal, said address comparator is controlled to compare the read/write target memory address with the repair target memory address in response to the control signal.