Pulsed wave Doppler ultrasound is commonly used in the assessment and diagnosis of cardiovascular diseases and blood flow abnormalities. Doppler techniques have gained clinical significance due to its safety, real-time performance and affordability. Most modern medical ultrasound systems have one or more Doppler modes. This work presents the development of a pulsed wave spectral Doppler module, which was integrated into a reconfigurable ultrasound system. The targeted system adopts a hardware-software partitioning scheme where a field programmable gate array (FPGA) handles the front-end processing and a PC performs the back-end processing. Two main factors were considered during the design of the Doppler module. First, the data transfer rate between hardware and software should be minimum. Second, the design should use as few of the FPGA resources as possible. Based on these criteria, the processing was divided after the range gate integration where the data rate drops significantly. In addition, a simple quadrature demodulator was used based on a digital switching mixer and a cascaded integrator comb (CIC) low pass filter. The design was implemented and integrated into the targeted system. The Doppler module was tested within the system environment using a string phantom and on human volunteers. The results showed that this simple design could achieve performance comparable to designs that are more sophisticated. However, it is limited by the number of available frequencies. Hence, it is suitable for systems with limited resources such as portable and handheld systems