This work demonstrates a system-on-chip circuitry for epileptic seizure detection. The circuitry contains a modified OpenRISC1200 processor core with on-chip Wishbone bus and interfaces circuitries, embedded 48KB SRAM, a multi-mode Sigma-Delta modulator and its digital filter, 7 pre-amplifiers and an analog multiplexer. The size of proposed circuitry is 2994 μm by 2994 μm as shown in Fig. 1(a), which was fabricated in TSMC 0.18um CMOS technology. The maximum operation frequency of designed SoC is 100 MHz. The fabricated SoC was mounted on a costumed printed circuit board (PCB) for functional and performance evaluation as shown in Fig. 1(b). The circuitry and PCB was then programed absent seizure detection algorithm proposed in ,  and apply to a Long-Evans rat with absent seizure to verify its real time performance. The experimental setup is shown in Fig 1(c). The designed SoC runs the seizure detection program in a closed-loop mode to detect 7-channel ECoG signals at 50 MHz, or 2-channel ECoG signals at 12.5 MHz. The designed SoC can also runs at an interactive mode to provide real-time interaction with LabView based GUI on a laptop computer for recording or additional real-time signal processing on the connected computer. The corresponding utility and programing environment for the designed SoC are also presented in the real-time seizure detection experiment shown in Fig. 1(c).