Most of existing field programmable gate array (FPGA) based watermarking algorithms have two primary weaknesses, large overhead and robustness. In this work, a robust low-overhead watermarking algorithm is proposed for intellectual property (IP) protection. The ownership is split into orderly small watermarks. The watermark positions are generated by the watermarks. Location mapping is performed to each position to make it not leak in verification. The real content of embedded watermarks is compressed to be one third of the original number. The configuration of small watermark has left lots of space for correcting. So, it can locate the attackers by checking each watermark. The experimental results illustrate a low-overhead on resource and delay. The efficiency and robustness of the proposed scheme are encouraging.