This article presents the integration of a 32-channel neuromodulation system on chip (SoC) that is developed for chronic implantation in humans. The application-specific integrated circuit (ASIC) offers low-noise recording, a state-of-the-art (SotA) neurostimulator capable of both current- and voltage-controlled stimulation with high-voltage compliance, on-chip 16-bit data digitization as well as safety features such as electrode impedance estimation and charge balancing. The chip communicates through two distinct SPI interfaces for independent command and data transfer. Thus, the developed system constitutes a fully digital, bidirectional 32-channel interface to the brain.