integ_rst :
An integration with reset operator for xreal-typed signals

The integ_rst primitive computes the time-integral of an xreal-typed input signal in. Its difference with the integ primitive is that it resets its output when its xbit-typed input rst is asserted. In other words, the integration is performed only when the input rst is at 0, according to the following equations:

    out = init_value + scale * integral(from 0 to t) of x(t) dt

for the output starting from t=0 with rst=0 and

    out = rst_value + scale * integral(from t_rst to t) of x(t) dt

for the output starting from t=t_rst with rst=0 where t_rst is the time when the input rst last fell to 0.

The parameter scale specifies the scale factor applied to the integral and the parameters init_value and rst_value specify the initial value and reset value of the integral, respectively.

The parameter mode determines the reset behavior of this primitive, namely, the output value when the input rst is 1. When mode is set to “reset” (by default), the output value is reset to rst_value as soon as the input rst rises to 1. On the other hand, when mode is set to “hold”, the output value is held at its last value while rst is at 1 and is reset to rst_value when rst falls back to 0.

            +       +                   +---+   +---+
           /|      /|                  /    |  /    |
    out   / |     / |     /     out   /     | /     | /
         /  |    /  |    /           /      |/      |/
            +---+   +---+                   +       +

            +---+   +---+               +---+   +---+
    rst  ---+   +---+   +--     rst  ---+   +---+   +--

         mode = 'reset'              mode = 'hold'

Input/Output Terminals

Name	I/O	Type	Description
out	output	xreal	output signal
in	input	xreal	input signal
rst	input	xbit	reset input

Parameters

Name	Type	Default	Unit	Description
scale	real	1.0	None	input scale factor
init_value	real	0.0	None	output initial value
rst_value	real	0.0	None	output reset value
mode	string	‘reset’	None	reset mode