Metering unit with enhanced DMA transfer

A method for monitoring power in a distributed power network, wherein a power-related, multi-phase waveform passes through a power line and zero-crossings of the waveform define its cycles, said method comprising the steps of:

• sensing desired phases of analog voltages and currents associated with said waveform;
• generating a timer output;
• simultaneously capturing intra-cycle voltage values and intra-cycle current values corresponding to each of said desired phases of said distributed power network;
• converting said intra-cycle voltage values and said intra-cycle current values into digital samples in response to said timer output;
• storing said digital samples in a FIFO buffer;
• providing a transfer signal to a processor upon the filling of the FIFO buffer for initiating a DMA transfer of said digital samples to a memory;
• generating a single source address to said FIFO buffer by said processor to transfer a portion of each digital sample from said FIFO buffer to said memory;
• altering said source address received by said FIFO buffer by DMA enhancement circuitry to transfer a remaining portion of each digital sample from said FIFO buffer to said memory during said DMA transfer while said address generated by said processor remains the same;
• and
• performing at least one power-related calculation for said distributed power network by directly using said digital samples in said memory.

A metering unit for monitoring power in a distributed power network, wherein a power-related, multi-phase waveform passes through a power line and zero-crossings of the waveform define its cycles, said metering unit comprising:

• an analog to digital converter producing digital samples from intra-cycle voltage values and intra-cycle current values and having a buffer, said buffer storing said digital samples;
• a memory coupled to said analog to digital converter ›for storing said digital;
• a processor including DMA controller circuitry responsive to a transfer signal from said analog to digital converter upon the filling of said buffer for initiating a DMA transfer of said digital samples from said buffer to said memory, said DMA controller circuitry generating a source address to said buffer to transfer a portion of each digital sample from said buffer to said memory;
• and
• DMA enhancement circuitry altering said source address received by said buffer to transfer a remaining portion of each digital sample from said buffer to said memory during said DMA transfer while said source address generated by said DMA controller circuitry remains the same.

A method for monitoring power in a distributed power network, wherein a power-related, multi-phase waveform passes through a power line and zero-crossings of the waveform define its cycles, said method comprising the steps of:

• converting intra-cycle voltage values and intra-cycle current values into digital samples;
• storing said digital samples in a buffer;
• providing a transfer signal to a processor upon the filling of the buffer to initiate a DMA transfer of said digital samples to a memory;
• generating an address to said buffer by said processor to transfer a portion of each digital sample from said buffer to said memory;
• and
• altering said address received by said buffer by DMA enhancement circuitry to transfer a remaining portion of each digital sample from said buffer to said memory during said DMA transfer while said address generated by said processor remains the same.