27.2.2 MCG Control Register 2 (MCG_C2)
Address: 4006_4000h base + 1h offset = 4006_4001h
Bit
7
6
5
4
3
2
1
0
Read
Write
Reset
0
0
0
0
0
0
0
1
MCG_C2 field descriptions
Field
Description
7–6
Reserved
This field is reserved.
This read-only field is reserved and always has the value 0.
5–4
RANGE0
External Clock Source Frequency Range Select
Selects the frequency for the crystal oscillator or the external clock source. See the Oscillator (OSC)
chapter for more details and refer to the chip datasheet for the frequency ranges used.
00
Low frequency range selected for the crystal oscillator or the external clock source.
01
High frequency range selected for the crystal oscillator or the external clock source.
10
Very high frequency range selected for the crystal oscillator or the external clock source.
11
Very high frequency range selected for the crystal oscillator or the external clock source. Same effect
as 10.
3
HGO0
Crystal Oscillator Operation Mode Select
Selects the crystal oscillator mode of operation. See the Oscillator (OSC) chapter for more details.
0
Configure crystal oscillator for low-power operation.
1
Configure crystal oscillator for high-gain operation.
2
EREFS0
External Clock Source Select
Selects the source for the external reference clock. See the Oscillator (OSC) chapter for more details.
0
External clock requested.
1
Oscillator requested.
1
Reserved
This field is reserved.
This read-only field is reserved and always has the value 0.
0
IRCS
Low-frequency Internal Reference Clock Select
Controls the LIRC to work at 2 MHz or 8 MHz mode.
0
LIRC is in 2 MHz mode.
1
LIRC is in 8 MHz mode.
Memory map and register definition
KL27 Sub-Family Reference Manual , Rev. 5, 01/2016
436
Freescale Semiconductor, Inc.