Test of a first draft 8 bit integrator
(First Published November 2008, Update May 13 2017)
The simple integrator just uses the integration formula
STATUS = STATUS+INP13-INN13
As long as de absolute difference | INP13-INN13 | much smaller than the
full range of the integrator the integration will take some time until
the integrator starts clipping.
If | INP13-INN13 | is close to
full range the integrator will start clipping after few or in extreme
cases after just one clock edge.
Both cases are tested in a test bench.
The result is shown here.
Fig. 1: Testing the integrator.
Between t=31 and t=230 INP and INN just differ by 1. each clock edge
the signal at the output is just incremented by one.
Between t=230 and t=300 the difference is -1 and the output is
decremented accordingly.
Between t=530 and t= 830 the difference is bigger and the integrator
reaches its upper limit after just 2 clocks.
Similarly after t=830 the integrator reaches it's lower limit after 3
clocks.