
DS3105
79
Register Name:
MCR10
Register Description:
Master Configuration Register 10
Register Address:
48h
Bit #
7
6
5
4
3
2
1
0
Name
—
SRFPIN
UFSW
EXTSW
PBOFRZ
PBOEN
—
Default
1
0
see below
0
1
0
Bit 6: SRFAIL Pin Enable (SRFPIN). When this bit is set to 1, the SRFAIL pin is enabled. When enabled the
SRFAIL pin follows the state of the SRFAIL status bit in the
MSR2 register. This gives the system a very fast
indication of the failure of the current reference. See Section
7.5.3.0 = SRFAIL pin disabled (high impedance)
1 = SRFAIL pin enabled
Bit 5: Ultra-Fast Switching Mode (UFSW). See Section
7.6.4. 0 = Disabled
1 = Enabled. The current reference source is disqualified after less than three missing clock cycles.
Bit 4: External Reference Switching Mode (EXTSW). This bit enables external reference switching mode. In this
mode, if the SRCSW pin is high the T0 DPLL is forced to lock to input IC3 (if the priority of IC3 is nonzero) or IC5 (if
the priority of IC3 is zero) whether or not the selected input has a valid reference signal. If the SRCSW pin is low
the device is forced to lock to input IC4 (if the priority of IC4 is nonzero) or IC6 (if the priority of IC4 is zero) whether
or not the selected input has a valid reference signal. During reset the default value of this bit is latched from the
SRCSW pin. This mode only controls the T0 DPLL. The T4 DPLL is not affected. See Section
7.6.5.0 = Normal operation
1 = External switching mode
Bit 3: Phase Build-Out Freeze (PBOFRZ). This bit freezes the current input-output phase relationship and does
not allow further phase build-out events to occur. This bit affects phase build-out in response to reference switching
0 = Not frozen
1 = Frozen
Bit 2: Phase Build-Out Enable (PBOEN). When this bit is set to 1 a phase build-out event occurs every time the
T0 DPLL changes to a new reference, including exiting the holdover and free-run states. When this bit is set to 0,
the T0 DPLL locks to the new source with zero degrees of phase difference. See Section
7.7.7.Register Name:
MCR11
Register Description:
Master Configuration Register 11
Register Address:
4Bh
Bit #
7
6
5
4
3
2
1
0
Name
—
T4T0
—
Default
0
Bit 4: T4 or T0 Path Select (T4T0). This bit specifies which path is being accessed when reads or writes are made
0 = T0 path
1 = T4 path