okCPLL22150 Class Reference

Container class which holds the appropriate configuration parameters for a Cypress 22150 PLL. More...

Public Member Functions
	okCPLL22150 ()
	Default constructor.
double	GetCrystalLoad () const
	Get the crystal load capacitance.
int	GetDiv1Divider () const
	Get the divider value for divider #1.
int	GetDiv2Divider () const
	Get the divider value for divider #2.
DividerSource	GetDiv1Source () const
	Get the source for divider #1.
DividerSource	GetDiv2Source () const
	Get the source for divider #2.
double	GetOutputFrequency (int output) const
	Gets the current output frequency for a particular output.
ClockSource	GetOutputSource (int output) const
	Gets the current output clock source for a particular output.
void	GetProgrammingInfo (okTPLL22150ProgramInfo buf) const
	Loads 'buf' with alternating address/data for programming the PLL.
double	GetReference () const
	Get the current reference crystal frequency.
double	GetVCOFrequency () const
	Get the VCO output frequency.
int	GetVCOP () const
	Get the VCO P(total) value.
int	GetVCOQ () const
	Get the VCO Q(total) value.
void	InitFromProgrammingInfo (const okTPLL22150ProgramInfo buf)
	Generates the PLL data from I2C programming data.
bool	IsExternalOscillatorEnabled () const
	Returns true if external oscillator is enabled.
bool	IsOutputEnabled (int output) const
	Returns true is the specified output is enabled.
void	SetCrystalLoad (double capload)
	Set the crystal load capacitance.
void	SetReference (double freq, bool extosc)
	Sets the reference crystal frequency for output frequency computations.
void	SetDiv1 (DividerSource divsrc, int n)
	Set the values for divider #1.
void	SetDiv2 (DividerSource divsrc, int n)
	Set the values for divider #2.
void	SetOutputSource (int output, ClockSource clksrc)
	Set the source for a particular output.
void	SetOutputEnable (int output, bool enable)
	Set the output enable for a particular output.
bool	SetVCOParameters (int p, int q)
	Set the VCO P(total) and Q(total) values.

Detailed Description

This is a container class which holds the appropriate configuration parameters for a Cypress 22150 PLL. The PLL has a single VCO but mutliple outputs with frequencies derived from dividers and switching blocks.

Python Note: Under Python, this class is simply called PLL22150. Therefore, if you import the ok library, you would refer to this class as ok.PLL22150.

Note that this object does not communicate with the XEM. That is, it does not reflect the state of the actual PLL. It is simply a container class used to configure and query the on-board PLL.

Typically, PLL settings will be set with the FrontPanel application and stored in EEPROM. In some cases, however, you may want your code to configure the PLL. Refer to the Cypress documentation to see how the various settings affect the output. The following example configures the VCO to operate at 400 MHz and sets up two outputs at 100 MHz and 50 MHz.

okCPLL22150 *pll = new okCPLL22150
pll->SetReference(48.0f, false);
pll->SetVCOParameters(400, 48);
pll->SetDiv1(okCPLL22150::DivSrc_VCO, 4);
pll->SetOutputSource(0, okCPLL22150::ClkSrc_Div1ByN);
pll->SetOutputEnable(0, true);
pll->SetDiv2(okCPLL22150::DivSrc_VCO, 8);
pll->SetOutputSource(1, okCPLL22150::ClkSrc_Div2ByN);
pll->SetOutputEnable(1, true);

At this point, the pll instance may be passed to okCUsbFrontPanel::SetPLLConfiguration to configure the on-board PLL. You can also use okCPLL22150::GetOutputConfiguration to verify that the output frequency is set properly.