mcf51jf128 Freescale Semiconductor, Inc, mcf51jf128 Datasheet - Page 437

• Manufacturer Part Number: mcf51jf128
• Description: Mcf51jf128 Reference Manual
• Manufacturer: Freescale Semiconductor, Inc

20.3.2 MCG Control 2 Register (MCG_C2)
Address: MCG_C2 is FFFF_8400h base + 1h offset = FFFF_8401h
Freescale Semiconductor, Inc.
Reserved
Reserved
RANGE
EREFS
HGO
Field
Reset
Field
Read
5–4
Write
LP
7
6
3
2
1
Bit
Controls whether or not the internal reference clock remains enabled when the MCG enters Stop mode.
0
1
This read-only bit is reserved and always has the value zero.
This read-only bit is reserved and always has the value zero.
Frequency Range Select
Selects the frequency range for the crystal oscillator or external clock source. Refer to the Oscillator
(OSC) chapter for more details.
00
01
1X
High Gain Oscillator Select
Controls the crystal oscillator mode of operation. Refer to the Oscillator (OSC) chapter for more details.
0
1
External Reference Select
Selects the source for the external reference clock. Refer to the Oscillator (OSC) chapter for more details.
0
1
Low Power Select
7
0
0
Internal reference clock is disabled in Stop mode.
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.
Configure crystal oscillator for low-power operation.
Configure crystal oscillator for high-gain operation.
External reference clock requested.
Oscillator requested.
Encoding 0 — Low frequency range selected for the crystal oscillator of 32 kHz to 40 kHz (reset
default).
Encoding 1 — High frequency range selected for the crystal oscillator of 1 MHz to 8 MHz.
Encoding 2 — Very high frequency range selected for the crystal oscillator of 8 MHz to 32 MHz.
0
0
6
MCF51JF128 Reference Manual, Rev. 2, 03/2011
MCG_C1 field descriptions (continued)
MCG_C2 field descriptions
Table continues on the next page...
0
5
RANGE
Preliminary
0
4
Description
Description
Chapter 20 Multipurpose Clock Generator (MCG)
HGO
0
3
EREFS
0
2
LP
0
1
IRCS
0
0
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