Electronic systems and methods for integrated, automatic, medium-quality audio
View Patent ↗A semiconductor device includes a single substrate including circuitry to implement a processor, a memory coupled to the processor, an audio interface module configured to provide data in pulse-code modulation (PCM) format having a first signal to noise ratio (SNR), and a medium quality speaker module configured to receive the PCM data, convert the data from the PCM format to a pulse-width modulation (PWM) format independently of the processor, and provide the data in the PWM format having a second SNR to at least one general purpose input-output pin on the substrate, the first SNR is greater than the second SNR.
1. A semiconductor device comprising:
a single substrate including circuitry to implement:
a processor;
a memory coupled to the processor;
an audio interface module configured to provide data in pulse-code modulation (PCM) format having a first signal to noise ratio (SNR); and
a medium quality speaker (MQS) module configured to receive the PCM data, convert the data from the PCM format to a pulse-width modulation (PWM) format independently of the processor, and provide the data in the PWM format having a second SNR to at least one general purpose input-output (GPI/O) pin on the substrate, the first SNR is greater than the second SNR.
2. The semiconductor device of claim 1 wherein the data in the PCM format includes a first number of bits and the data in the PWM format includes less than the first number of bits.
3. The semiconductor device of claim 1 , wherein the first SNR is greater than or equal to approximately 90 decibels and the second SNR is less than approximately 70 decibels.
4. The semiconductor device of claim 1 wherein the MQS module includes
a converter that includes XOR logic to convert two's complement data in the PCM format to unsigned magnitude data in the PWM format.
5. The semiconductor device of claim 1 wherein the MQS module includes
a serial to parallel converter configured to convert the PCM data from serial to parallel format.
6. The semiconductor device of claim 5 wherein the MQS module includes
a filter configured to receive the PCM data in parallel format, oversample the PCM data, reduce noise in the PCM data, and reduce the number of bits in the PCM data to generate filtered PCM data.
7. The semiconductor device of claim 1 wherein
the MQS module operates independently of sampling frequency of the data in the PCM and PWM formats.
8. The semiconductor device of claim 1 further comprising:
at least one of a group consisting of:
a digital to analog converter implemented on the substrate and coupled to receive the data in the PCM format and to output the data as an analog signal, and
an audio encoder/decoder implemented as circuitry on a second substrate coupled to receive the data in the PCM format and to output the data as at least one of a digital and an analog signal.
9. The semiconductor device of claim 4 further comprising:
a counter configured to receive a frame sync signal from the data in the PCM format and a clock signal, and output a counter signal; and
a comparator configured to receive the counter signal, a first PWM signal representing a first pulse width of a first channel of the data, and a second PWM signal representing a second pulse width of a second channel of the data, and generate a first PWM output for the first channel and a second PWM output for the second channel, wherein
the first and second PWM outputs are a first state when the counter signal is less than respective ones of the first and second PWM signals and the first PWM outputs are a second state when the counter signal is greater than or equal to the respective ones of the first and second PWM signals.
10. The semiconductor device of claim 9 further comprising:
a first flip-flop circuit configured to receive the first PWM output of the comparator; and
a second flip-flop circuit configured to receive the second PWM output of the comparator, the first and second flip-flop circuits are coupled to respective first and second GPIO pins.
11. A semiconductor device comprising:
a processor;
an audio interface module coupled to provide data in pulse-code modulation (PCM) format;
a medium quality speaker (MQS) module configured to receive the PCM data, convert the PCM data to a pulse-width modulation (PWM) format independently of the processor, and provide the data in PWM format to a general purpose input/output (I/O) pin on the substrate, the MQS module including:
a serial to parallel converter configured to convert the PCM data from serial to parallel format;
a filter configured to oversample and remove noise from the PCM data in parallel format to generate filtered PCM data in two's complement format, wherein the filtered PCM data includes fewer bits than the PCM data in the parallel format; and
a converter that uses one of a group consisting of: XOR logic and most significant bit (MSB) inversion logic, to convert the filtered PCM data to unsigned magnitude data in the PWM format.
12. The semiconductor device of claim 11 wherein
the data in PCM format has a first signal to noise ratio (SNR); and
the data from the PWM format has a second SNR, the first SNR is greater than the second SNR.
13. The semiconductor device of claim 11 wherein
the data in the PCM format includes a first number of bits and the data in the PWM format includes less than the first number of bits.
14. The semiconductor device of claim 12 wherein
the first SNR is greater than or equal to approximately 90 decibels and the second SNR is less than approximately 70 decibels.
15. The semiconductor device of claim 11 wherein
the MQS module operates independently of sampling frequency of the data in the PCM and PWM formats.
16. The semiconductor device of claim 11 further comprising:
at least one of a group consisting of:
a digital to analog converter implemented on the substrate and coupled to receive the data in the PCM format and to output the data as an analog signal, and
an audio encoder/decoder implemented as circuitry on a second substrate coupled to receive the data in the PCM format and to output the data as at least one of a digital and an analog signal.
17. The semiconductor device of claim 11 further comprising:
a counter configured to receive a frame sync signal from the data in the PCM format and a clock signal, and output a counter signal; and
a comparator configured to receive the counter signal, a first PWM signal representing a first pulse width of a first channel of the data, and a second PWM signal representing a second pulse width of a second channel of the data, and generate a first PWM output for the first channel and a second PWM output for the second channel, wherein
the first and second PWM outputs are a first state when the counter signal is less than respective ones of the first and second PWM signals and the first PWM outputs are a second state when the counter signal is greater than or equal to the respective ones of the first and second PWM signals.
18. The semiconductor device of claim 17 further comprising:
a first flip-flop circuit configured to receive the first PWM output of the comparator; and
a second flip-flop circuit configured to receive the second PWM output of the comparator, the first and second flip-flop circuits are coupled to respective first and second GPIO pins.
19. A method of converting data from pulse-coded modulation (PCM) format to pulse-width modulation format comprising:
oversampling and removing noise from the data in a first PCM format to generate filtered PCM data in two's complement format, wherein the filtered PCM data includes fewer bits than the data in the first PCM format;
converting the filtered PCM data to unsigned magnitude data in a PWM format using one of a group consisting of: XOR logic and most significant bit (MSB) inversion logic; and
comparing the unsigned magnitude data to a counter value to determine when an output of the comparator changes state
latching the output of the comparator for each of a plurality of clock cycles and providing latched comparator signals to a general purpose input/output pin of a semiconductor device, wherein the oversampling, converting, comparing and latching are performed by circuitry implemented on a single substrate, and a signal-to-noise ratio (SNR) of the data in the first PCM format is greater than or equal to approximately 90 decibels and a SNR of the latched comparator signals is less than approximately 70 decibels.
20. The method of claim 19 further comprising:
the oversampling, converting, comparing and latching are performed independently of sampling frequency of the data in the first PCM format and the unsigned magnitude data in the PWM format.