Motorola TMS320C6711D warranty PLL and PLL controller

SPRS292A − OCTOBER 2005 − REVISED NOVEMBER 2005

PLL and PLL controller

The device includes a PLL and a flexible PLL controller peripheral consisting of a prescaler (D0) and four dividers (OSCDIV1, D1, D2, and D3). The PLL controller is able to generate different clocks for different parts of the system (i.e., DSP core, Peripheral Data Bus, External Memory Interface, McASP, and other peripherals). Figure 8 illustrates the PLL, the PLL controller, and the clock generator logic.

+3.3 V

EMI filter

For Use in System

C1 C2

10 ∝F 0.1 ∝F

PLLHV

CLKMODE0
CLKIN				PLLOUT
		PLLREF
		DIVIDER D0			PLLEN (PLL_CSR.[0])
	1	/1, /2,	PLL
		..., /32		1	DIVIDER D1†
	0	ENA	x4 to x25
Reserved					/1, /2,		SYSCLK1
				0
					..., /32		(DSP Core)
			D1EN (PLLDIV1.[15])		ENA
		D0EN (PLLDIV0.[15])			DIVIDER D2†
					/1, /2,
							SYSCLK2
					..., /32
	OSCDIV1						(Peripherals)
CLKOUT3			D2EN (PLLDIV2.[15])		ENA
	/1, /2,
	..., /32				DIVIDER D3
	ENA
					/1, /2,
OD1EN (OSCDIV1.[15])					..., /32		SYSCLK3
					ENA
			D3EN (PLLDIV3.[15])
ECLKIN
(EMIF Clock Input)					1	0	EKSRC Bit
							(DEVCFG.[4])
C6711D DSP					EMIF
						ECLKOUT

†Dividers D1 and D2 must never be disabled. Never write a “0” to the D1EN or D2EN bits in the PLLDIV1 and PLLDIV2 registers.

NOTES: A. Place all PLL external components (C1, C2, and the EMI Filter) as close to the C67x DSP device as possible. For the best performance, TI recommends that all the PLL external components be on a single side of the board without jumpers, switches, or components other than the ones shown.

B.For reduced PLL jitter, maximize the spacing between switching signals and the PLL external components (C1, C2, and the EMI Filter).

C.The 3.3-V supply for the EMI filter must be from the same 3.3-V power plane supplying the I/O voltage, DVDD.

D.EMI filter manufacturer TDK part number ACF451832-333, -223, -153, -103. Panasonic part number EXCCET103U.

Figure 8. PLL and Clock Generator Logic

46 POST OFFICE BOX 1443 • HOUSTON, TEXAS 77251−1443