Added "icepll" PLL parameters calculator

3 files changed, 199 insertions, 0 deletions

diff --git a/icepll/.gitignore b/icepll/.gitignore
new file mode 100644
index 0000000..385a169
--- /dev/null
+++ b/icepll/.gitignore
@@ -0,0 +1,3 @@
+icepll
+icepll.o
+icepll.d
diff --git a/icepll/Makefile b/icepll/Makefile
new file mode 100644
index 0000000..9a190f6
--- /dev/null
+++ b/icepll/Makefile
@@ -0,0 +1,22 @@
+include ../config.mk
+LDLIBS = -lm -lstdc++
+CXXFLAGS = -MD -O0 -ggdb -Wall -std=c++11 -I/usr/local/include
+
+all: icepll
+
+icepll: icepll.o
+
+install: all
+	mkdir -p $(DESTDIR)$(PREFIX)/bin
+	cp icepll $(DESTDIR)$(PREFIX)/bin/icepll
+
+uninstall:
+	rm -f $(DESTDIR)$(PREFIX)/bin/icepll
+
+clean:
+	rm -f icepll *.o *.d
+
+-include *.d
+
+.PHONY: all install uninstall clean
+
diff --git a/icepll/icepll.cc b/icepll/icepll.cc
new file mode 100644
index 0000000..261cf0a
--- /dev/null
+++ b/icepll/icepll.cc
@@ -0,0 +1,174 @@
+//
+//  Copyright (C) 2015  Clifford Wolf <clifford@clifford.at>
+//
+//  Permission to use, copy, modify, and/or distribute this software for any
+//  purpose with or without fee is hereby granted, provided that the above
+//  copyright notice and this permission notice appear in all copies.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+//  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+//  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+//  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+//  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+//  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+//  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+//
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <math.h>
+
+const char *binstr(int v, int n)
+{
+	static char buffer[16];
+	char *p = buffer;
+
+	for (int i = n-1; i >= 0; i--)
+		*(p++) = ((v >> i) & 1) ? '1' : '0';
+	*(p++) = 0;
+
+	return buffer;
+}
+
+void help(const char *cmd)
+{
+	printf("\n");
+	printf("Usage: %s [options]\n", cmd);
+	printf("\n");
+	printf("    -i <input_freq_mhz>\n");
+	printf("        PLL Input Frequency (default: 12 MHz)\n");
+	printf("\n");
+	printf("    -o <output_freq_mhz>\n");
+	printf("        PLL Output Frequency (default: 60 MHz)\n");
+	printf("\n");
+	printf("    -S\n");
+	printf("        Disable SIMPLE feedback path mode\n");
+	printf("\n");
+	exit(1);
+}
+
+int main(int argc, char **argv)
+{
+	double f_pllin = 12;
+	double f_pllout = 60;
+	bool simple_feedback = true;
+
+	int opt;
+	while ((opt = getopt(argc, argv, "i:o:S")) != -1)
+	{
+		switch (opt)
+		{
+		case 'i':
+			f_pllin = atof(optarg);
+			break;
+		case 'o':
+			f_pllout = atof(optarg);
+			break;
+		case 'S':
+			simple_feedback = false;
+			break;
+		default:
+			help(argv[0]);
+		}
+	}
+
+	if (optind != argc)
+		help(argv[0]);
+
+	bool found_something = false;
+	double best_fout = 0;
+	int best_divr = 0;
+	int best_divf = 0;
+	int best_divq = 0;
+
+	if (f_pllin < 10 || f_pllin > 133) {
+		fprintf(stderr, "Error: PLL input freqency %.3f MHz is outside range 10 MHz - 133 MHz!\n", f_pllin);
+		exit(1);
+	}
+
+	if (f_pllout < 16 || f_pllout > 275) {
+		fprintf(stderr, "Error: PLL output freqency %.3f MHz is outside range 16 MHz - 275 MHz!\n", f_pllout);
+		exit(1);
+	}
+
+	for (int divr = 0; divr <= 15; divr++)
+	{
+		double f_pfd = f_pllin / (divr + 1);
+		if (f_pfd < 10 || f_pfd > 133) continue;
+
+		for (int divf = 0; divf <= 127; divf++)
+		{
+			if (simple_feedback)
+			{
+				double f_vco = f_pfd * (divf + 1);
+				if (f_vco < 533 || f_vco > 1066) continue;
+
+				for (int divq = 1; divq <= 6; divq++)
+				{
+					double fout = f_vco * exp2(-divq);
+
+					if (fabs(fout - f_pllout) < fabs(best_fout - f_pllout) || !found_something) {
+						best_fout = fout;
+						best_divr = divr;
+						best_divf = divf;
+						best_divq = divq;
+						found_something = true;
+					}
+				}
+			}
+			else
+			{
+				for (int divq = 1; divq <= 6; divq++)
+				{
+					double f_vco = f_pfd * (divf + 1) * exp2(divq);
+					if (f_vco < 533 || f_vco > 1066) continue;
+
+					double fout = f_vco * exp2(-divq);
+
+					if (fabs(fout - f_pllout) < fabs(best_fout - f_pllout) || !found_something) {
+						best_fout = fout;
+						best_divr = divr;
+						best_divf = divf;
+						best_divq = divq;
+						found_something = true;
+					}
+				}
+			}
+		}
+	}
+
+	double f_pfd = f_pllin / (best_divr + 1);;
+	double f_vco = f_pfd * (best_divf + 1);
+
+	if (!simple_feedback)
+		f_vco *= exp2(best_divq);
+
+	if (!found_something) {
+		fprintf(stderr, "Error: No valid configuration found!\n");
+		exit(1);
+	}
+
+	printf("\n");
+
+	printf("F_PLLIN:  %8.3f MHz (given)\n", f_pllin);
+	printf("F_PLLOUT: %8.3f MHz (requested)\n", f_pllout);
+	printf("F_PLLOUT: %8.3f MHz (achieved)\n", best_fout);
+
+	printf("\n");
+
+	printf("FEEDBACK: %s\n", simple_feedback ? "SIMPLE" : "NON_SIMPLE");
+	printf("F_PFD: %8.3f MHz\n", f_pfd);
+	printf("F_VCO: %8.3f MHz\n", f_vco);
+
+	printf("\n");
+
+	printf("DIVR: %2d (4'b%s)\n", best_divr, binstr(best_divr, 4));
+	printf("DIVF: %2d (7'b%s)\n", best_divf, binstr(best_divf, 7));
+	printf("DIVQ: %2d (3'b%s)\n", best_divq, binstr(best_divq, 3));
+
+	printf("\n");
+
+	return 0;
+}