Design of the ADPCM synthetic voice chip

In this paper, combination of the Pulse Width Modulation (PWM) technology and the Adaptive Differential Pulse Code Modulation (ADPCM) technology, design a digital synthetic voice chip. First of all, verilog hardware description language used to complete the design of decoding module, then the decoded digital voice signals transformed into PWM waves by using the PWM technology so as to drive the loudspeaker directly and sound. This type of voice synthetic output has such advantages as small power consumption, low cost and practical features.