SM3E Data Sheet #:
TM054
Page 15 of 36 Rev: 04 Date: 01/26/11
Copyright 2011 The Connor-Winfield Corp. All Rights Reserved
Specifications subject to change without notice
Register Descriptions and Operation continued
Phase_Offset, 0x0e (R/W)
Bit7~Bit0
The2’scomplementvalueofphaseoffsetbetweenMasterOutputmoduleandSlaveOutputmodule,rangesfrom-32nSto+31.75nS
PositiveValue:MasterOutputrisingedgeleadsSlaveOutput
NegativeValue:MasterOutputrisingedgelagsSlaveOutput
In slave mode, the slave’s outputs may be phase shifted -32nS to +31.75nS in .25nS increments, relative to M/S ac-
cording to the contents of the Phase_Offset register, to compensate for the path length of the M/S to M/S connection.
If a phase offset is used, then the two SM3E devices would typically be written to the appropriate phase offset val-
ues for the respective path lengths of each Master to Slave connection, to ensure that the same relative output signal
phases will persist through master/slave switches.
Calibration, 0x0f (R/W)
Bit7~Bit0
2’scomplementvalueoflocaloscillatordigitalcalibrationin0.05ppmresolution
To digitally calibrate the free running clock synthesized from the internal clock, this register is written with a value cor-
responding to the known frequency offset of the oscillator from the nominal center frequency.
Fr_Pulse_Width, 0x10 (R/W)
Bit7~Bit4
Bit3~Bit0
Reserved
PulsewidthforM/Sclockoutput,
1-15multiplesoftheSync_Clkclockperiod.
BITS 4 and 5 of the Ctl_Mode register determine if the M/S 8 kHz output is 50% duty cycle or pulsed (high going)
outputs. When they are pulsed, the Fr_Pulse_Width register determines the width. Width is the register value multiple of
the Sync_Clk clock period. Valid values are 1 - 15.
Reset default is 0001. Writing to 0000 maps to 0001.
DPLL_Status, 0x11 (R)
Bit7~Bit5
Bit4
Bit3
Bit2
Bit1
Bit0
Reserved
HoldOver
Locked
LossofLock
LossofSignal
Build
Available
1:Locked
1:LossofLock
1:Noactivity
Complete
1:Avail.
0:Notlocked
0:Nolossoflock
onactive
1:Complete
0:Notavail.
reference
0:Incomplete
0:Activeref-
erencesignal
present
Bit 0 indicates the presence of a signal on the selected reference.
Bit 1 indicates a loss of lock (LOL). Loss of lock will be asserted if lock is not achieved within the specified time for the
stratum level of operation, or lock is lost after being established previously. LOL will not be asserted for automatic refer-
ence switches.
Bit 2 indicates successful phase lock. It will typically be set in <700 seconds for Stratum 3E with a good reference. It
will indicate “not locked” if lock is lost.
Bit 3 indicates if a Hold Over history is available.
Bit 4 indicates when a new Hold Over history has been sucessfully built and transferred to the active Hold Over his-
tory. See Detailed Description section under Interrupts and Reference Change in Autonomous Mode and Interrupts in
Manual Mode