Integrator

It's written for C programmers, but

For an "integrator" you just add the input to an accumulator once each sample of your DSP algorithm. Note that it doesn't really integrate; the closest you can come in sampled time is to sum the samples. Note also that you must establish a sampling time for your digital signal processing -- if you're sampling some external signal with an ADC and sampling it out with a DAC at the same speed you'll probably want to run the internal algorithm at that speed as well, just watch your integrator depths.

Just know that you can't realize an ANALOG integrator into an FPGA which is what you would need for your Sigma Delta converter pursuit.