MC9S08GT16 MOTOROLA [Motorola, Inc], MC9S08GT16 Datasheet - Page 121

• Manufacturer Part Number: MC9S08GT16
• Description: Microcontrollers
• Manufacturer: MOTOROLA [Motorola, Inc]

REFST — Reference Clock Status
LOLS — FLL Loss of Lock Status
LOCK — FLL Lock Status
LOCS — Loss Of Clock Status
ERCS — External Reference Clock Status
Freescale Semiconductor
The REFST bit indicates which clock reference is currently selected by the Reference Select circuit.
The LOLS bit is an indication of FLL lock status. If LOLS is set, it remains set until cleared by
software or an MCU reset.
The LOCK bit indicates whether the FLL has acquired lock. The LOCK bit is cleared in off,
self-clocked, and FLL bypassed modes.
The LOCS bit is an indication of ICG loss of clock status. If LOCS is set, it remains set until cleared
by software on an MCU reset.
The ERCS bit is an indication of whether or not the external reference clock (ICGERCLK) meets the
minimum frequency requirement.
1 = Crystal/Resonator selected.
0 = External Clock selected.
1 = FLL has unexpectedly lost lock since LOLS was last cleared, LOLRE determines action taken.
0 = FLL has not unexpectedly lost lock since LOLS was last cleared.
1 = FLL is currently locked.
0 = FLL is currently unlocked.
1 = ICG has lost clock since LOCS was last cleared, LOCRE determines action taken.
0 = ICG has not lost clock since LOCS was last cleared.
1 = External reference clock is stable, frequency requirement is met.
0 = External reference clock is not stable, frequency requirement is not met.
CLKST[1:0]
00
01
10
11
Table 7-9. CLKST Clock Mode Status
MC9S08GB/GT Data Sheet, Rev. 2.3
FLL bypassed, external reference
FLL engaged, external reference
FLL engaged, internal reference
Clock Status
Self-clocked
ICG Registers and Control Bits
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