MC9S08GB60 Datasheet, PDF (121/290 Pages) Motorola, Inc – Microcontrollers

ICG Registers and Control Bits
Table 7-9. CLKST Clock Mode Status
CLKST[1:0]
00
01
10
11
Clock Status
Self-clocked
FLL engaged, internal reference
FLL bypassed, external reference
FLL engaged, external reference
REFST — Reference Clock Status
The REFST bit indicates which clock reference is currently selected by the Reference Select circuit.
1 = Crystal/Resonator selected.
0 = External Clock selected.
LOLS — FLL Loss of Lock Status
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.
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.
LOCK — FLL Lock Status
The LOCK bit indicates whether the FLL has acquired lock. The LOCK bit is cleared in off,
self-clocked, and FLL bypassed modes.
1 = FLL is currently locked.
0 = FLL is currently unlocked.
LOCS — Loss Of Clock Status
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.
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.
ERCS — External Reference Clock Status
The ERCS bit is an indication of whether or not the external reference clock (ICGERCLK) meets the
minimum frequency requirement.
1 = External reference clock is stable, frequency requirement is met.
0 = External reference clock is not stable, frequency requirement is not met.
MC9S08GB/GT Data Sheet, Rev. 2.3
Freescale Semiconductor
121