/* 
   CPPLL Hand Calculator, OC, 2007
   Example : CaPPeLLo -Icp 10.0E-6 -Wn 1.0E6 -N 128 -Kvco 45.0E9 -Wi 40.0E6 -Ksi 0.9
*/

#include "iostream"
#include "math.h"

float PI = 3.141592653589793;
float C1, C3, C3min, C3max, R, Tau, Rmax, Bl, Kvco, Ko;
float Wn, Wi, Ksi, Icp;
float K, proportionalTerm, integralTerm;
bool  isRmaxOk, isStable;
int   N;

//___________________________________________________________
void PrintUsageMessage(char *nameOfTheTool) {
	fprintf(stderr, "Switces of %s (2nd Order CP-PLL parameter calculator) are :\n\
   -Kvco      : VCO gain in Hz/V\n\
   -N         : Feedback divide ratio\n\
   -Wi 	      : Reference frequency in Hz\n\
   -Wn        : Natural frequency of the loop in Hz\n\
   -Icp	      : Charge pump current in A\n\
   -Ksi	      : Desired dumping factor\n\
   ", nameOfTheTool);
}

//___________________________________________________________
void PrintDUT(char *nameOfTheTool) {
	fprintf(stderr, "\n\
Feed-Back System Under Consideration in %s :\n\
 \n\
       Kp        Icp      Tau        Kvco\n\
      +-----+   +----+   +-----+    +-----+        \n\     
Wi -->| PFD |-->| CP |-->| LPF |--->| VCO |--+--> Wo\n\
      +--+--+   +----+   +-----+    +-----+  |\n\
         |                                   |\n\
         |  Wo/N         +----+     N*Wi     |\n\
         +---------------| %N |<-------------+\n\
                         +----+\n\
 \n\
Low Pass Filter Configuration :\n\
 \n\
+-----+\n\
| LPF |   ==>   +----+-------+----+\n\
+-----+              |       |\n\
                     |       |\n\
                     |      +-+\n\
                     | C3   | | R\n\
                   -----    | | \n\
                   -----    | |\n\
                     |      +-+\n\
                     |       |\n\
                     |       | C1\n\
                     |     -----\n\
                     |     -----\n\
                     |       |\n\
                     |       |\n\
                   -----   ----- \n\
                    ---     ---\n\
                     -       -\n\
\n", nameOfTheTool, nameOfTheTool);
}

//___________________________________________________________
int SetParameters(int argc, char **argv) {	
	if (argc <= 1) {
		PrintUsageMessage(argv[0]);
		exit(0);
	} 
	int optCtr = 1;
	if (strcmp(argv[1], "-?") == 0 || strcmp(argv[1], "-help") == 0 || strcmp(argv[1], "--help") == 0 ) {
		PrintUsageMessage(argv[0]);
		exit(0);
	}
	while (optCtr != argc) {
		if (0 == strcmp(argv[optCtr], "-N")) {
        	optCtr++;
			sscanf(argv[optCtr], "%d", &N);
			optCtr++;
		} else if (0 == strcmp(argv[optCtr], "-Wn")) {
			optCtr++;
			sscanf(argv[optCtr], "%f", &Wn);
            Wn=Wn*2.0*PI; // convert to rad/s
			optCtr++;
        } else if (0 == strcmp(argv[optCtr], "-Kvco")) {
            optCtr++;
			sscanf(argv[optCtr], "%f", &Kvco);
            Ko=Kvco*2.0*PI; // convert to rad/s/V
			optCtr++;
        } else if (0 == strcmp(argv[optCtr], "-Wi")) {
			optCtr++;
			sscanf(argv[optCtr], "%f", &Wi);
            Wi=Wi*2.0*PI; // convert to rad/s
			optCtr++;
        } else if (0 == strcmp(argv[optCtr], "-Ksi")) {
			optCtr++;
            sscanf(argv[optCtr], "%f", &Ksi);
			optCtr++;
		} else if (0 == strcmp(argv[optCtr], "-Icp")) {
            optCtr++;
            sscanf(argv[optCtr], "%f", &Icp);
			optCtr++;
        } else {
            PrintDUT(argv[0]);
      		PrintUsageMessage(argv[0]);
      		exit(1);
    	}
	}
return 0;
}

//___________________________________________________________
int Calculate() {
    C1=(Ko*Icp)/(2*PI*Wn*Wn*N);
    C3max=0.1*C1;                
    C3min=0.02*C1;
    C3=(C3min+C3max)/2.0;
    Tau=(2*Ksi)/Wn;
    R=Tau/C1;
    K=(Ko*Icp*R)/(2*PI*N);
    Rmax=(2*PI*Wi*N)/(Ko*Icp);
    Bl=((Wn/2.0)*(Ksi+1.0/(4.0*Ksi)));
    proportionalTerm=Icp*R;
    integralTerm=Icp/(C3*Wi);
    if (R <= Rmax) isRmaxOk = true;
    else isRmaxOk = false;
    if (K*Tau < Wi*Tau) isStable = true;
    else isStable = false;
    return 0;
}

//___________________________________________________________
int Output() {
    printf("Loop Parameters : \n\n");
    printf("Wi in Mrad/s              : %f\n", (float)(Wi/1.0E6));
    printf("Wo in Grad/s              : %f\n", (float)(Wi*N*1.0E-9));
    printf("Wn in Mrad/s              : %f\n", (float)(Wn*1.0E-6));
    printf("N                         : %f\n", (float)(N));
    printf("Ksi                       : %f\n", (float)(Ksi));
    printf("Ko in Grad/s/V            : %f\n", (float)(Ko*1.0E-9));
    printf("Icp in uA                 : %f\n", (float)(Icp*1.0E6));
    printf("C1 in  pF                 : %f\n", (float)(C1/1.0E-12));
    printf("C3min in pF               : %f\n", (float)(C3min*1.0E12));
    printf("C3max in pF               : %f\n", (float)(C3max*1.0E12));
    printf("C3 in pF                  : %f\n", (float)(C3*1.0E12));
    printf("R in Ohm                  : %f\n", (float)(R));
    printf("Rmax in Ohm               : %f (", (float)(Rmax));
    if (!isRmaxOk) printf("ERROR - R>Rmax, Conflict !..)\n");
    else printf("R<Rmax, OK !..)\n");
    printf("K in rad/s                : %f\n", (float)(K));
    printf("Tau in us                 : %f\n", (float)(Tau*1.0E6));
    printf("KTau2                     : %f\n", (float)(K*Tau));
    printf("WiTau2                    : %f (",(float)(Wi*Tau));
    if (!isStable) printf("UNSTABLE !..)\n");
    else printf("Stable !..)\n");
    printf("Proportional term in mV   : %f\n", (float)(proportionalTerm*1.0E3));
    printf("Integral term in mV       : %f\n", (float)(integralTerm*1.0E3));
    printf("Bl in Mrad/s              : %f\n\n", (float)(Bl/1.0E6)); 
    return 0;
}

//___________________________________________________________
int main(int argc, char **argv) {
    SetParameters(argc, argv);
    Calculate();
    PrintDUT(argv[0]);
    Output();
    return 0;
}