Texas Instruments TMS3320C5515 manual Clock Generator Control Register 1 CGCR1 1C20h

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1.4.4.1Clock Generator Control Register 1 (CGCR1) [1C20h]

The clock generator control register 1 (CGCR1) is shown in Figure 1-6and described in Table 1-13.

Figure 1-6. Clock Generator Control Register 1 (CGCR1) [1C20h]

15	14	13	12	11			8
Reserved		Reserved	PLL_PWRDN			M
R/W-0		R/W-0	R/W-1			R/W-0
7	6	5	4	3	2	1	0
			M
			R/W-0

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

Table 1-13. Clock Generator Control Register 1 (CGCR1) Field Descriptions

Bit	Field	Value	Description
15	Reserved	0	This bit must be set to 1 for normal operation.
14-13	Reserved	0	Reserved. This bit must be always written to be zero.
12	PLL_PWRDN		PLL power down bit. This bit is used to power down the PLL when it is not being used.
		0	PLL is powered up.
		1	PLL is powered down.
11-0	M	0-FFFh	PLL multiplier value bits. These bits define the PLL multiplier value. Multiplier value = M + 4.

1.4.4.2Clock Generator Control Register 2 (CGCR2) [1C21h]

The clock generator control register 2 (CGCR2) is shown in Figure 1-7and described in Table 1-14.

Figure 1-7. Clock Generator Control Register 2 (CGCR2) [1C21h]

15	14	12	11	0
RDBYPASS		Reserved		RDRATIO
R/W-0		R-0		R/W-0

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

Table 1-14. Clock Generator Control Register 2 (CGCR2) Field Descriptions

Bit	Field	Value	Description
15	RDBYPASS		Reference divider bypass control. When this bit is set to 1 the PLL reference divider is bypassed
			(i.e., FPLLIN = FCLKREF). When this bit is set to 0, the reference clock to the PLL is divided by the
			reference divider (i.e., FPLLIN = FCLKIN / (RDRATIO+4)). The RDRATIO bits specify the divider value.
		0	Use the reference divider.
		1	Bypass the reference divider.
14-12	Reserved	0	Reserved.
11-0	RDRATIO	0-FFFh	Divider ratio bits for the reference divider. Divider value = RDRATIO + 4. For example, setting
			RDRATIO = 0 means divide the input clock rate by 4.

30	System Control	SPRUFX5A –October 2010 –Revised November 2010
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