Ics Status Register (Ics_S) - NXP Semiconductors MC9S08SU16 Reference Manual

Register definition

12.3.5 ICS Status Register (ICS_S)

Address: 1848h base + 4h offset = 184Ch
Bit 7
Read LOLS
Write w1c
Reset 0
Field
7 Loss of Lock Status
LOLS
Indicates the lock status for the FLL. LOLS is set when lock detection is enabled and after acquiring lock,
the FLL output frequency has fallen outside the lock exit frequency tolerance, from ±4.7% to ±5.97%.
ICS_C4[LOLIE] determines whether an interrupt request is made when set. LOLS is cleared by reset or by
writing a logic 1 to LOLS when LOLS is set. Writing a logic 0 to LOLS has no effect.
0 FLL has not lost lock since LOLS was last cleared.
1 FLL has lost lock since LOLS was last cleared.
6 Lock Status
LOCK
Indicates whether the FLL has acquired lock. Lock detection is disabled when FLL is disabled. If the lock
status bit is set then changing the value of any of the following fields IREFS, RDIV[2:0], or, if in FEI or FBI
modes, SCTRIM[7:0] will cause the lock status bit to clear and stay cleared until the FLL has reacquired
lock. Stop mode entry will also cause the lock status bit to clear and stay cleared until the FLL has
reacquired lock.
0 FLL is currently unlocked.
1 FLL is currently locked.
5 This field is reserved.
Reserved This read-only field is reserved and always has the value 0.
4 Internal Reference Status
IREFST
Indicates the current source for the reference clock. This field does not update immediately after a write to
ICS_C1[IREFS] due to internal synchronization between clock domains.
0 Source of reference clock is external clock.
1 Source of reference clock is internal clock.
3–2 Clock Mode Status
CLKST
Indicates the current clock mode. This field doesn't update immediately after a write to ICS_C1[CLKS] due
to internal synchronization between clock domains.
00 Output of FLL is selected.
01 FLL Bypassed, internal reference clock is selected.
10 FLL Bypassed, external reference clock is selected.
11 Reserved.
Reserved This field is reserved.
This read-only field is reserved and always has the value 0.
196
6 5
LOCK 0 IREFST
0 0
ICS_S field descriptions
MC9S08SU16 Reference Manual, Rev. 5, 4/2017
4 3
CLKST
1 0
Description
2 1
0
0 0
NXP Semiconductors
0
0