Texas Instruments TMS320DM643x manual 5. PLL Control Register PLLCTL, PLL Controller Registers

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PLL Controller Registers

5.4.3 PLL Control Register (PLLCTL)

The PLL control register (PLLCTL) is shown in Figure 5-5and described in Table 5-7.

Figure 5-5. PLL Control Register (PLLCTL)

31										16
					Reserved
					R-0
15	9	8	7	6	5	4	3	2	1	0
Reserved		CLKMODE	Reserved		PLLENSRC	PLLDIS	PLLRST	Rsvd	PLLPWRDN	PLLEN
R-0		R/W-0		R-1h	R/W-1	R/W-1	R/W-0	R-0	R/W-1	R/W-0

LEGEND: R/W = Read/Write; R = Read only; -n= value after reset

Table 5-7. PLL Control Register (PLLCTL) Field Descriptions

Bit	Field	Value	Description
31-9	Reserved	0	Reserved
8	CLKMODE		Reference clock selection
		0	Internal oscillator. If the device reference clock source is a crystal at MXI/CLKIN pin, the internal
			oscillator must be selected as the clock source.
		1	CLKIN square wave. This mode applies if the device reference clock source is a square wave at
			MXI/CLKIN pin. When this mode is selected, the PLLC turns off the internal oscillator's bias resistor
			to save power.
7-6	Reserved	1	Reserved
5	PLLENSRC	0	This bit must be cleared to 0 before PLLEN will have any effect.
4	PLLDIS		Asserts DISABLE to PLL.
		0	PLL disable is de-asserted.
		1	PLL disable is asserted. PLL output is disabled and not toggling.
3	PLLRST		Asserts RESET to PLL if supported.
		0	PLL reset is asserted. See device-specific data manual for the PLL reset time required.
		1	PLL reset is not asserted.
2	Reserved	0	Reserved
1	PLLPWRDN		PLL power-down. After powering up the PLL (PLLPWRDN 1 to 0 transition), you must wait for the
			PLL to stabilize. See device-specific data manual for the PLL stabilization time.
		0	PLL operational.
		1	PLL power-down.
0	PLLEN		PLL mode enable.
		0	Bypass mode
		1	PLL mode, not bypassed

50 PLL Controller SPRU978E–March 2008

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