SIM_SOPT2 field descriptions (continued)
Field
Description
00
Clock disabled
01
IRC48M clock
10
OSCERCLK clock
11
MCGIRCLK clock
23–22
FLEXIOSRC
FlexIO Module Clock Source Select
Selects the clock source for the FlexIO transmit and receive clock.
00
Clock disabled
01
IRC48M clock
10
OSCERCLK clock
11
MCGIRCLK clock
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
IRC48M clock
17–16
Reserved
This field is reserved.
This read-only field is reserved and always has the value 0.
15–8
Reserved
This field is reserved.
This read-only field is reserved and always has the value 0.
7–5
CLKOUTSEL
CLKOUT select
Selects the clock to output on the CLKOUT pin.
000
Reserved
001
Reserved
010
Bus clock
011
LPO clock (1 kHz)
100
LIRC_CLK
101
Reserved
110
OSCERCLK
111
IRC48M clock (IRC48M clock can be output to PAD only when chip VDD is 2.7-3.6 V)
4
RTCCLKOUTSEL
RTC Clock Out Select
Selects either the RTC 1 Hz clock or the OSC clock to be output on the RTC_CLKOUT pin.
0
RTC 1 Hz clock is output on the RTC_CLKOUT pin.
1
OSCERCLK clock is output on the RTC_CLKOUT pin.
Reserved
This field is reserved.
This read-only field is reserved and always has the value 0.
Chapter 12 System Integration Module (SIM)
KL27 Sub-Family Reference Manual , Rev. 5, 01/2016
Freescale Semiconductor, Inc.
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