Test resource partitioning is an efficient method to reduce the test cost.This paper presents a novel and efficient code

i.e.variable-tail code

for test data compression.Theoretical analysis and experimental study show that the variable-tail code can provide the higher compression efficiency than Golomb.It is suitable for different test sets and could provide the high compression ratio.The decoder of the variable-tail code is simple and easy to be implemented.In order to achieve higher compression ratio

an efficient test vectors reordering algorithm (ERA) incorporating a dynamic X-bit assignment procedure is presented.Experimental results demonstrated the efficiency of the proposed code and algorithm.