commit a555e59e7d5d9604a3eb3a609d3efb1cd38c5b1e
Author: PaulStoffregen <paul@pjrc.com>
Date:   Fri Jun 24 04:54:45 2016 -0700

    Init PHY & PLL - gotta start somewhere!

diff --git a/k66_usbhost.ino b/k66_usbhost.ino
new file mode 100644
index 0000000..416cf5c
--- /dev/null
+++ b/k66_usbhost.ino
@@ -0,0 +1,60 @@
+// usb host experiments....
+
+void setup()
+{
+	while (!Serial) ; // wait
+	print("USB Host Testing");
+	MCG_C1 |= MCG_C1_IRCLKEN;  // enable MCGIRCLK 32kHz
+	OSC0_CR |= OSC_ERCLKEN;
+	SIM_SOPT2 |= SIM_SOPT2_USBREGEN; // turn on USB regulator
+	SIM_SOPT2 &= ~SIM_SOPT2_USBSLSRC; // use IRC for slow clock
+	print("power up USBHS PHY");
+	SIM_USBPHYCTL |= SIM_USBPHYCTL_USBDISILIM; // disable USB current limit
+	SIM_USBPHYCTL = SIM_USBPHYCTL_USBDISILIM | SIM_USBPHYCTL_USB3VOUTTRG(6); // pg 237
+	SIM_SCGC3 |= SIM_SCGC3_USBHSDCD | SIM_SCGC3_USBHSPHY | SIM_SCGC3_USBHS;
+	print("init USBHS PHY & PLL");
+	// init process: page 1681-1682
+	USBPHY_CTRL &= ~USBPHY_CTRL_SFTRST;	// CTRL pg 1698
+	USBPHY_CTRL &= ~USBPHY_CTRL_CLKGATE;
+	USBPHY_PLL_SIC |= USBPHY_PLL_SIC_PLL_POWER;
+	USBPHY_PLL_SIC |= USBPHY_PLL_SIC_PLL_DIV_SEL(1);  // PLL_SIC pg 1708
+	// wait for the PLL to lock
+	int count=0;
+	while ((USBPHY_PLL_SIC & USBPHY_PLL_SIC_PLL_LOCK) == 0) {
+		count++;
+	}
+	print("PLL locked, waited ", count);
+
+	// sanity check, connect 470K pullup & 100K pulldown and watch D+ voltage change
+	//USBPHY_ANACTRL_CLR = (1<<10); // turn off both 15K pulldowns... works! :)
+
+	SIM_SOPT2 = SIM_SOPT2 & (~SIM_SOPT2_CLKOUTSEL(7)) | SIM_SOPT2_CLKOUTSEL(3); // LPO 1kHz
+	SIM_SOPT2 = SIM_SOPT2 & (~SIM_SOPT2_CLKOUTSEL(7)) | SIM_SOPT2_CLKOUTSEL(2); // Flash
+	SIM_SOPT2 = SIM_SOPT2 & (~SIM_SOPT2_CLKOUTSEL(7)) | SIM_SOPT2_CLKOUTSEL(6); // XTAL
+	SIM_SOPT2 = SIM_SOPT2 & (~SIM_SOPT2_CLKOUTSEL(7)) | SIM_SOPT2_CLKOUTSEL(7); // IRC 48MHz
+	SIM_SOPT2 = SIM_SOPT2 & (~SIM_SOPT2_CLKOUTSEL(7)) | SIM_SOPT2_CLKOUTSEL(4); // MCGIRCLK
+	CORE_PIN9_CONFIG = PORT_PCR_MUX(5);  // CLKOUT on PTC3 Alt5 (Arduino pin 9)
+
+
+
+}
+
+
+void loop()
+{
+	// do nothing (yet)
+}
+
+void print(const char *s)
+{
+	Serial.println(s);
+	delay(10);
+}
+
+void print(const char *s, int num)
+{
+	Serial.print(s);
+	Serial.println(num);
+	delay(10);
+}
+