Clock Source Selection

Functions
ALT_CLK_t	alt_clk_source_get (ALT_CLK_t clk)
ALT_STATUS_CODE	alt_clk_source_set (ALT_CLK_t clk, ALT_CLK_t ref_clk)

Detailed Description

This API group provide access and control to the input reference clock source selection for a clock or PLL.

Function Documentation

alt_clk_source_get()

ALT_CLK_t alt_clk_source_get

(

ALT_CLK_t

clk

)

Get the input reference clock source selection value for the specified clock or PLL.

NOTE: This function returns a clock value even though clk may specify a clock that does not have a selectable input reference clock source. In this case, the clock value returned is the static clock source for the specified clock. For example calling alt_clk_source_get() with clk set to ALT_CLK_MAIN_PLL will return ALT_CLK_OSC1.

Parameters

clk	The clock or PLL to retrieve the input reference clock source selection value for.

Returns

The clock's currently selected input reference clock source.

alt_clk_source_set()

ALT_STATUS_CODE alt_clk_source_set	(	ALT_CLK_t	clk,
		ALT_CLK_t	ref_clk
	)

Set the specified clock's input reference clock source selection.

Parameters

clk	The clock or PLL to set the input reference clock source selection for.
ref_clk	The input reference clock source selection value.

Return values

ALT_E_SUCCESS	The operation was succesful.
ALT_E_ERROR	The operation failed.
ALT_E_BAD_ARG	The clk argument designates a clock that does not have a selectable input reference clock source.
ALT_E_INV_OPTION	The ref_clk argument designates a clock that is an invalid reference clock source for the specified clock.