Capacitive interface for coupling between a music chip and audio player

DETAILED DESCRIPTION OF THE DRAWINGS The present invention capacitive interface is utilized for transmission of encoded audio data between a solid state audio player and a digital recording medium having prerecorded music stored thereon, referred to herein as a semiconductor music chip.
Referring to FIG.
1, there is shown a block diagram of one preferred embodiment of a solid state audio system 10 which utilizes the present invention capacitive interface 20.
The audio system 10 includes an audio player 12 operated by means of a digital signal processor (DSP) 14 and having a music chip 16 coupled thereto by means of the capacitive interface 20.
The music chip 16 is essentially a memory device having digital data stored therein which corresponds to pre-recorded music.
The pre-recorded audio data is stored in the chip 16 in a compressed format by means of an audio coding algorithm.
The algorithm reduces the amount of digital information necessary to be stored from a master recording, while still reproducing essentially the same audio quality when the data is read.
Encoding by means of the algorithm is necessary in order to store sufficient quantities of data so that the music on the chip may have a time of play comparable to that of current day albums.
The main hardware architecture of the audio player 12 of FIG.
1 consists of, besides the DSP 14, a stereo coder/decoder (codec) 18, keypad 22, display 24, and associated interface logic in the form of an applications specific integrated circuit (ASIC) 26.
The audio player 12 is responsible for decoding the encoded bit stream read from the music chip 16 and outputting the music through an output device such as speakers or headphones 28.
Parameters of the PAC algorithm are downloaded into external RAM 30 when a chip 16 is loaded into the player 12 in order to assist in the decoding process.
Referring to FIG.
2, a more detailed illustration is shown of the interface 20 between the music chip 16 and audio player 12.
The audio player 12 includes an address shift register 32 and data shift register 34 which are coupled to the DSP 14 over associated address and data buses 36, 38