MCG_C1 field descriptions
Field
Description
7–6
CLKS
Clock Source Select
Selects the clock source for MCGOUTCLK .
00
Encoding 0 — Output of FLL is selected.
01
Encoding 1 — Internal reference clock is selected.
10
Encoding 2 — External reference clock is selected.
11
Encoding 3 — Reserved.
5–3
FRDIV
FLL External Reference Divider
Selects the amount to divide down the external reference clock for the FLL. The resulting frequency must
be in the range 31.25 kHz to 39.0625 kHz (This is required when FLL/DCO is the clock source for
MCGOUTCLK . In FBE mode, it is not required to meet this range, but it is recommended in the cases
when trying to enter a FLL mode from FBE).
000
If RANGE 0 = 0 , Divide Factor is 1; for all other RANGE 0 values, Divide Factor is 32.
001
If RANGE 0 = 0 , Divide Factor is 2; for all other RANGE 0 values, Divide Factor is 64.
010
If RANGE 0 = 0 , Divide Factor is 4; for all other RANGE 0 values, Divide Factor is 128.
011
If RANGE 0 = 0 , Divide Factor is 8; for all other RANGE 0 values, Divide Factor is 256.
100
If RANGE 0 = 0 , Divide Factor is 16; for all other RANGE 0 values, Divide Factor is 512.
101
If RANGE 0 = 0 , Divide Factor is 32; for all other RANGE 0 values, Divide Factor is 1024.
110
If RANGE 0 = 0 , Divide Factor is 64; for all other RANGE 0 values, Divide Factor is 1280 .
111
If RANGE 0 = 0 , Divide Factor is 128; for all other RANGE 0 values, Divide Factor is 1536 .
2
IREFS
Internal Reference Select
Selects the reference clock source for the FLL.
0
External reference clock is selected.
1
The slow internal reference clock is selected.
1
IRCLKEN
Internal Reference Clock Enable
Enables the internal reference clock for use as MCGIRCLK.
0
MCGIRCLK inactive.
1
MCGIRCLK active.
0
IREFSTEN
Internal Reference Stop Enable
Controls whether or not the internal reference clock remains enabled when the MCG enters Stop mode.
0
Internal reference clock is disabled in Stop mode.
1
Internal reference clock is enabled in Stop mode if IRCLKEN is set or if MCG is in FEI, FBI, or BLPI
modes before entering Stop mode.
21.3.2 MCG Control 2 Register (MCG_C2)
Address: 4006_4000h base + 1h offset = 4006_4001h
Bit
7
6
5
4
3
2
1
0
Read
Write
Reset
1
0
0
0
0
0
0
0
Chapter 21 Multipurpose Clock Generator (MCG)
KL02 Sub-Family Reference Manual, Rev. 2.1, July 2013
Freescale Semiconductor, Inc.
267