1  component updown "Counts up or down, with optional limits and wraparound behavior";
 2  pin in bit countup "Increment count when this pin goes from 0 to 1";
 3  pin in bit countdown "Decrement count when this pin goes from 0 to 1";
 4  pin in bit reset "Reset count when this pin goes from 0 to 1";
 5  pin out s32 count "The current count";
 6  param rw bit clamp "If TRUE, then clamp the output to the min and max parameters.";
 7  param rw bit wrap "If TRUE, then wrap around when the count goes above or below the min and max parameters.  Note that wrap implies (and overrides) clamp.";
 8  param rw s32 max = 0x7FFFFFFF "If clamp or wrap is set, count will never exceed this number";
 9  param rw s32 min "If clamp or wrap is set, count will never be less than this number";
10  variable int oldup;
11  variable int olddown;
12  variable int first = 1;
13  function _ nofp "Process inputs and update count if necessary";
14  license "GPL";
15  
16  ;;
17  
18  FUNCTION(_) {
19  	hal_s32_t temp_count = count;
20  	if (first) {
21  		oldup=countup;
22  		olddown=countdown;
23  		first=0;
24  	}
25  	if ((!oldup) && (countup)) { // positive edge, count up
26  		temp_count++;
27  	}
28  	if ((!olddown) && (countdown)) { // positive edge, count down
29  		temp_count--;
30  	}
31  	if (reset) {
32  		temp_count=0;
33  	}
34  	if (wrap) {
35  		if (temp_count > max)
36  			temp_count = min;
37  		else if (temp_count < min)
38  			temp_count = max;
39  	} else if (clamp) {
40  		if (temp_count > max)
41  			temp_count = max;
42  		else if (temp_count < min)
43  			temp_count = min;
44  	}
45  	count = temp_count;
46  	oldup = countup;
47  	olddown = countdown;
48  }