Efficient built-in self-test techniques for memory-based FFT processors

Efficient built-in self-test techniques for memory-based FFT processors are proposed. The memory-based architecture is suitable for high computation point applications such as ADSL and OFDM systems. The FFT processor is first divided into the memory part and the logic part which can be tested under the supervision of the same BIST controller. The BIST controller can not only perform traditional memory test algorithms but also generates test patterns required for the logic part. The adopted memory test algorithm can be programmed by the users which covers different types of memory faults. For the logic part, the single cell fault model is assumed. Our BIST architecture tests both parts simultaneously such that the test time can be reduced greatly. The hardware overhead of our approach is also very low since novel design-for-testability techniques are applied for the logic part which mainly consists of multipliers. An experimental chip is designed and implemented with Synopsys synthesis tools. Experimental results show that the hardware overhead of the BIST architecture is only 4.06%. The fault coverage of the memory part depends on the March algorithm adopted. For the logic part, we can achieve 100% cell fault coverage with only 16 test patterns.