Power, Reset, and Clock Management
8.1.12.2.40 CM_CLKSEL_DPLL_PERIPH Register (offset = 9Ch) [reset = 0h]
CM_CLKSEL_DPLL_PERIPH is shown in
and described in
.
This register provides controls over the DPLL.
Figure 8-123. CM_CLKSEL_DPLL_PERIPH Register
31
30
29
28
27
26
25
24
DPLL_SD_DIV
R/W-0h
23
22
21
20
19
18
17
16
Reserved
Reserved
DPLL_MULT
R-0h
R-0h
R/W-0h
15
14
13
12
11
10
9
8
DPLL_MULT
R/W-0h
7
6
5
4
3
2
1
0
DPLL_DIV
R/W-0h
LEGEND: R/W = Read/Write; R = Read only; W1toCl = Write 1 to clear bit; -n = value after reset
Table 8-131. CM_CLKSEL_DPLL_PERIPH Register Field Descriptions
Bit
Field
Type
Reset
Description
31-24
DPLL_SD_DIV
R/W
0h
Sigma-Delta divider select (
2-255).
This factor must be set by s/w to ensure optimum jitter performance.
DPLL_SD_DIV = CEILING ([DPLL_MULT/(D1)] * CLKINP
/ 250), where CLKINP is the input clock of the DPLL in MHz).
Must be set with M and N factors, and must not be changed once
DPLL is locked.
0x0 = Reserved : Reserved
0x1 = Reserved1 : Reserved
23
Reserved
R
0h
22-20
Reserved
R
0h
19-8
DPLL_MULT
R/W
0h
DPLL multiplier factor (2 to 4095).
This register is automatically cleared to 0 when the DPLL_EN field in
the *CLKMODE_DPLL* register is set to select MN Bypass mode.
(equal to input M of DPLL
M=2 to
4095 => DPLL multiplies by M).
0x0 = 0 : Reserved
0x1 = 1 : Reserved
7-0
DPLL_DIV
R/W
0h
DPLL divider factor (0 to 255) (equal to input N of DPLL
actual division factor is N+1).
659
SPRUH73H – October 2011 – Revised April 2013
Power, Reset, and Clock Management (PRCM)
Copyright © 2011–2013, Texas Instruments Incorporated