A data processing device includes a memory, a direct memory access controller including a receiving module configured to receive data coming from outside the device and for writing the data in a main buffer memory of the memory, and a processing unit programmed to read and process data written by the receiving module in a work area of the main buffer memory. The main buffer memory is divided between a used space, where the receiving module is configured not to write, and free space, where the receiving module is configured to write. The processing unit is further programmed to define the work area, and the direct memory access controller includes a buffer memory manager configured to free data written in the main buffer memory, by defining a location of this data as a free space, only when this data is outside the work area.