Abstract: Audio data processing circuitry 300 includes a plurality of analog inputs 101 for receiving analog audio data and a digital input 105 for receiving digital audio data. A analog mixer 312 mixes analog data received at said plurality of analog inputs 101 to generate a mixed analog audio stream. An analog-to-digital converter 313 converts the mixed analog audio stream to a digital audio stream and a digital mixer 315 mixes digital data received at the digital input 105 with the digital audio stream from the analog mixer 312 to generate a mixed digital audio stream.

Abstract: A processing system 100 is disclosed which includes a system master 101, a system bus 102 coupled to the master, and a plurality of bus interface circuits 106 coupled to bus 102. A first one of the bus interfaces 106 includes a mapping signal input coupled to the master and a mapping signal output, the first bus interface 106 operable to latch-in at least one first selected address bit presented by the master on the system bus in response to a mapping enable signal received at the mapping signal input from the master 101. A second bus interface 106 is provided coupled to the bus 102 and having a mapping signal input coupled to the mapping signal output of first bus interface 106, the second bus interface 106 operable to latch-in at least one second selected address bit presented by the master 101 on the bus 102 in response to a second mapping enable signal received at the mapping input of the second bus interface 106 from the first bus interface 106.

Abstract: A method of operating a multiple processor device. A first word of a sequence of words is received in a register. A target processor is determined from the first word and the target processor is interrupted. An input ready bit is set and first word from in the register is read with the target processor. A number of words in the sequence to follow the first word determined from the first word. A word counter is set and the input ready bit is cleared with the target processor. The target processor is returned to main code execution.

Abstract: An audio decoder 100 for operating on a received compressed audio data stream compressed using an algorithm employing transform encoding and a bit allocation routine. A first processor 200 performs a first set of operations on the received compressed audio data stream including parsing the compressed audio data stream, recovering data fields within the compressed audio data stream, calculating a bit allocation, and passing frequency domain coefficients to shared memory. A second digital signal processor 100b performs a second set of operations on data passed from the first digital signal processor to shared memory including performing inverse transform operations on the data passed from the first digital signal processor.

Abstract: Digital-to-analog conversion circuitry 100 is shown including a path for processing data in a 1-bit format. First portion of an analog finite impulse response filter 300 includes pre-selected number of delay elements 301 for receiving stream of data in the 1-bit format and outputting a plurality of signals in response. A switched capacitor digital-to-analog converter 106 forms a second portion of the finite impulse response filter 301 and has a plurality of elements each receiving one of the plurality of signals as selected to effectuate a set of filter coefficients, converter 106 summing the plurality of signals and outputting an analog data stream.

Abstract: A method of concealing errors received in a stream of data by a multiprocessor system having a first digital signal processor for initial processing of incoming data and a second digital signal processor for processing data passed from the first processor. The method includes the steps of detecting an error in an incoming frame of the stream of data with the first processor, sending an error message from the first to the second processor, halting transmission of the remainder of the frame to the second processor, and processing a frame of dummy data with the second processor. The frame of dummy data is passed to a processing engine forming a portion of the second processor to maintain data pipelining. Interprocessor communications between the first and second processors is established by handshaking through an interprocessor communications register, wherein the first processor detects an error in a frame of data and sends a message to the second processor.