Digital signal processing apparatus

Abstract

A digital signal processing apparatus for converting an analog signal to a digital signal and digitally processing the digital signal is disclosed. The apparatus includes a modulation part for performing pulse density modulation on the analog signal and outputting a pulse density modulation signal, a memory for storing a conversion program for converting the pulse density modulation signal to pulse code modulation data, and a CPU for receiving the pulse density modulation signal from the modulation part and converting the received pulse density modulation signal to pulse code modulation data according to the conversion program stored in the memory.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing an exemplary configuration of a digital signal processing apparatus according to an embodiment of the present invention;

FIG. 2 is a block diagram showing a sigma-delta modulator according to an embodiment of the present invention;

FIG. 3 is a schematic diagram showing a data configuration of a memory according to an embodiment of the present invention;

FIG. 4 is a flowchart showing a process executed by a CPU according to an embodiment of the present invention;

FIG. 5 is a block diagram showing an exemplary hardware configuration of a decimation filter according to an embodiment of the present invention;

FIG. 6 is a detail flowchart showing a digital filtering process of Step S1-2 of FIG. 4 according to an embodiment of the present invention; and

FIG. 7 is a schematic diagram for describing an operation of a digital signal processing apparatus according to an embodiment of the present invention.

Claims

1. A digital signal processing apparatus for converting an analog signal to a digital signal and digitally processing the digital signal, the apparatus comprising: a modulation part for performing pulse density modulation on the analog signal and outputting a pulse density modulation signal;a memory for storing a conversion program for converting the pulse density modulation signal to the pulse code modulation data; anda CPU for receiving the pulse density modulation signal from the modulation part and converting the received pulse density modulation signal to pulse code modulation data according to the conversion program stored in the memory.

2. The digital signal processing apparatus as claimed in claim 1, wherein the CPU intermittently activates the conversion program, obtains the pulse density modulation signal from the modulation part, and converts the obtained pulse density modulation signal to the pulse code modulation data.

3. The digital signal processing apparatus as claimed in claim 2, further comprising a detection part for detecting the analog signal and supplying the analog signal to the modulation part.

4. The digital signal processing apparatus as claimed in claim 3, further comprising: a battery connected to the detection part;wherein the detection part includes a voltage detection part for detecting voltage of the battery,a current detection part for detecting charge current and discharge current of the battery,a temperature detection part for detecting temperature, anda selection part for selecting an analog signal output from one of the voltage detection part, the current detection part, and the temperature detection part and supplying the selected analog signal to the modulation part.

5. The digital signal processing apparatus as claimed in claim 4, wherein the analog signal indicates the charge current and discharge current of the battery,wherein the memory stores a remaining battery amount calculation program used for calculating the amount of charge remaining in the battery by integrating the charge current and discharge current of the battery, andwherein the CPU calculates the amount of charge remaining in the battery by integrating the pulse code modulation data of the charge current and discharge current of the battery according to the remaining battery amount calculation program stored in the memory.

6. The digital signal processing apparatus as claimed in claim 2, wherein the modulation part is a sigma-delta converter.

7. The digital signal processing apparatus as claimed in 3, wherein the detection part, the modulation part, the memory, and the CPU are mounted on the same semiconductor integrated circuit apparatus.