System and Peripheral Control Registers
177
SPNU503C – March 2018
Copyright © 2018, Texas Instruments Incorporated
Architecture
2.5.2.1
PLL Control Register 3 (PLLCTL3)
The PLLCTL3 register is shown in
and described in
; controls the settings of PLL2
(Clock Source 6 - FPLL).
Figure 2-59. PLL Control Register 3 (PLLCTL3) [offset = 00]
31
29
28
24
23
22
21
16
ODPLL2
PLLDIV2
Reserved
REFCLKDIV2
R/WP-1h
R/WP-Fh
R-0
R/WP-2h
15
0
PLL_MUL2
R/WP-5F00h
LEGEND: R/W = Read/Write; R = Read only; WP = Write in privileged mode only; -
n
= value after reset
Table 2-74. PLL Control Register 3 (PLLCTL3) Field Descriptions
Bit
Field
Value
Description
31-29
ODPLL2
Internal PLL Output Divider
OD2 = 1, ranges from 1 to 8.
f
post_ODCLK2
= f
output_CLK2
/ OD2
0
f
post_ODCLK2
= f
output_CLK2
/ 1
1h
f
post_ODCLK2
= f
output_CLK2
/ 2
:
:
7h
f
post_ODCLK2
= f
output_CLK2
/ 8
Note: PLL output clock is gated off, if ODPLL2 is changed while the PLL2 is active.
28-24
PLLDIV2
PLL2 Output Clock Divider
R2 = P 1, ranges from 1 to 32.
f
PLL2 CLK
= f
post_ODCLK2
/ R2
0
f
PLL2 CLK
= f
post_ODCLK2
/1
1h
f
PLL2 CLK
= f
post_ODCLK2
/2
:
:
1Fh
f
PLL2 CLK
= f
post_ODCLK2
/32
23-22
Reserved
0
Value has no effect on PLL operation.
21-16
REFCLKDIV2
Reference Clock Divider
NR2 = REFC 1, ranges from 1 to 64.
f
INTCLK2
= f
OSCIN
/ NR2
0
f
INTCLK2
= f
OSCIN
/1
1h
f
INTCLK2
= f
OSCIN
/2
:
:
3Fh
f
INTCLK2
= f
OSCIN
/64
Note: This value should not be changed while the PLL2 is active.
15-0
PLLMUL2
PLL2 Multiplication Factor
NF2 = (PLLMUL2 / 256) + 1, valid multiplication factors are from 1 to 256.
f
VCOCLK2
= f
INTCLK2
x NF2
User and privileged mode (read):
Privileged mode (write):
100h
f
VCOCLK2
= f
INTCLK2
x 1
:
:
5B00h
f
VCOCLK2
= f
INTCLK2
x 92
5C00h
f
VCOCLK2
= f
INTCLK2
x 93
:
:
FF00h
f
VCOCLK2
= f
INTCLK2
x 256