A multi-channel cochlear implant that can provide 16 channels of stimulation is presented in this paper. The speech processor is realized to run multiple speech process algorithms. A mixed analog and digital ASIC with 16 channels is designed, which supports 4 stimulus modes and provides a highest stimulus rate of 15k pulses per second per channel, and dynamic range of 60 dB with the 10 bit D/A converter. CIS speech process algorithm is introduced in the paper and fast filter bank implementation algorithm is studied to reduce the computation complexity.