The present invention provides an architecture of a memory Built-In Self Repair (BISR) controller for connecting to N memory instances, where N is a positive integer greater than 1. The architecture includes N groups of data ports, N BISR_SUBMOD modules for connecting to the N memory instances, and a CLK_IN input port and a BISR_IN input port for setting configuration of the memory BISR controller. Each of the N groups of data ports includes (1) a PHY_IN output port for connecting to input of a corresponding memory instance; (2) a PHY_OUT input port for connecting to output of the corresponding memory instance; (3) a LOG_IN input port for sending signals to the corresponding memory instance; and (4) a LOG_OUT output port for receiving signals from the corresponding memory instance. Each of the N BISR_SUBMOD modules includes a flip-flop, a first mux and a second mux. The CLK_IN input port is connected to clock inputs of all N flip-flops of the memory BISR controller. The BISR_IN input port is connected to data input of a first flip-flop, and output of a K-th flip-flop is connected to input of a (K+1)-th flip-flop, K=1, 2, . . . , N-1. When at least one of the N memory instances is defective, the memory BISR controller may reconfigure connections among the N memory instances to use other memory instance(s) instead of the defective memory instance(s).