1 This paper describes a small and portable digital baseband module developed for Bluetooth wireless technology. To achieve portability and the small size, much of the Bluetooth baseband layer protocols are implemented in software running on the embedded microcontroller while the minimal tasks of low-level baseband processing, UART and USB interfaces, and audio CODEC are performed on the dedicated hardware blocks. The fully synthesizable baseband module was fabricated in a 0.25µm CMOS technology occupying 2.25×2.25mm2 area