where can I get more info on HSDC protocol?
Like you mention the sample rate is 8kHz, the clock frequency for the ADE7978 is 16.384MHz.
It all depends on what data you are trying to read at the 8kHz rate. The rate at which you can get information is different with each technique. With just SPI or I2C there is nothing to make it more efficient so each register read requires a separate communication.
To speed it up, there are a set of registers which can be bursted out with SPI or I2C, this means that only one read command needs to be sent and multiple register values will be returned one after the other.
Then the fastest method is with HSDC because it is similar to the burst modes except now the I2C line is still open for communication while HSDC bursts out the specified registers in parallel. These registers are the waveforms for each channel, active, reactive and apparent power registers for all 3 phases.
In summary, HSDC is just the fastest way to stream data out if waveforms or powers are of importance, the next fastest will be using the SPI burst mode. It all depends on how much data you want to pull out at 8kHz and what data that is.
A great resource on the HSDC protocol is in the data sheet which can be found on the product page: ADE7978 Product Page. On Page 102, the details about the protocol are explained, then Page 13 gives the timing parameters for the protocol.
Do you have any specific questions on HSDC which I can help with?
A note, HSDC uses the SPI lines therefore it can only be used when I2C is the selected communication method.
thanks for your reply
There are couple of things that I am not sure:
As I understand the sampling rate is 8KHZ at 24bits, so clock rate will be at least 192Kbps
I2C = 400KHZ clock
SPI = 2.5MHZ clock
HSDC = 8MHZ
so it is possible that I can read at 8KHZ data even with I2C interface?
so when will I need the HSDC? what are the benefits of this interface?
Thank you again
Retrieving data ...