NXP Semiconductors K22F series, Reference Manual, Page: 265 / 1407

SIM_SOPT2 field descriptions (continued)
Field Description
01 MCGFLLCLK , or MCGPLLCLK, or IRC48M clock as selected by SOPT2[PLLFLLSEL].
10 OSCERCLK clock
11 MCGIRCLK clock
25–24
Reserved
This field is reserved.
This read-only field is reserved and always has the value 0.
23–22
Reserved
This field is reserved.
This read-only field is reserved and always has the value 0.
21–19
Reserved
This field is reserved.
This read-only field is reserved and always has the value 0.
18
USBSRC
USB clock source select
Selects the clock source for the USB 48 MHz clock.
0 External bypass clock (USB_CLKIN).
1 MCGFLLCLK, or MCGPLLCLK, or IRC48M clock as selected by SOPT2[PLLFLLSEL], and then
divided by the USB fractional divider as configured by SIM_CLKDIV2[USBFRAC, USBDIV].
17–16
PLLFLLSEL
PLL/FLL clock select
Selects the high frequency clock for various peripheral clocking options.
00 MCGFLLCLK clock
01 MCGPLLCLK clock
10 Reserved
11 IRC48 MHz clock
15–13
Reserved
This field is reserved.
This read-only field is reserved and always has the value 0.
12
TRACECLKSEL
Debug trace clock select
Selects the core/system clock, or MCG output clock (MCGOUTCLK) as the trace clock source.
0 MCGOUTCLK
1 Core/system clock
11
Reserved
This field is reserved.
This read-only field is reserved and always has the value 0.
10
Reserved
This field is reserved.
This read-only field is reserved and always has the value 0.
9–8
FBSL
FlexBus security level
If flash security is enabled, then this field affects what CPU operations can access off-chip via the
FlexBus interface. This field has no effect if flash security is not enabled.
00 All off-chip accesses (instruction and data) via the FlexBus are disallowed.
01 All off-chip accesses (instruction and data) via the FlexBus are disallowed.
10 Off-chip instruction accesses are disallowed. Data accesses are allowed.
11 Off-chip instruction accesses and data accesses are allowed.
7–5
CLKOUTSEL
CLKOUT select
Selects the clock to output on the CLKOUT pin.
000 FlexBus CLKOUT
Table continues on the next page...
Chapter 12 System Integration Module (SIM)
K22F Sub-Family Reference Manual, Rev. 4, 08/2016
NXP Semiconductors 265