We propose a very high-throughput fully hardwired CABAC encoder for ultra-high resolution video. Our architecture includes hardwired circuits for binarization, context modeling, neighbor data access, and a six-stage pipelined binary arithmetic encoder (BAE). Our BAE can encode multiple bins per cycle. In order to keep up with the BAE throughput, we propose acceleration methods for the bin and context index generations of several types of frequent syntax elements (SE). We further propose a novel architecture that shortens the critical path of renormalization and bitstream generation. Our design can encode 1.42 bins per cycle on the average, and it achieves a throughput of 315 Mbin/sec. Simulation results show that it can real-time encode QFHD (3840×2176) video at 30fps or 1080HD (1920x1088) at 60 fps for H.264/AVC main profile, level 5.1 by running at 222 MHz. We have successfully integrated the proposed CABAC encoder into an H.264/AVC encoder system using an SoC platform₁.