ACS8514 Semtech Corporation, ACS8514 Datasheet - Page 56

• Manufacturer Part Number: ACS8514
• Description: Synchronous Equipment Timing Source Partner IC for 2nd T4 Dpll, Accurate Monitoring & Input Extender
• Manufacturer: Semtech Corporation

Revision 3.00 April 2007 © Semtech Corp.
Address(hex): 4D
Address(hex): 50
Register Name
freq_lim_
ph_loss
Register Name
ADVANCED COMMS & SENSING
Bit No.
Bit No.
Bit 7
[6:0]
Bit 7
[7:0]
7
cnfg_DPLL_soft_limit
Description
freq_lim_ph_loss
Bit to enable the phase lost indication when the
DPLL hits its hard frequency limit as programmed in
register 41h & 42h (cnfg_DPLL_freq_limit ). This
results in the DPLL entering the phase lost state any
time the DPLL tracks to the extent of its hard limit.
It applies to both the Monitor DPLL and the T4 DPLL
DPLL_soft_limit_value
Register to program to what extent either of the
DPLLs tracks a source before raising its soft
frequency alarm flag (Bits 5 and 4 of register 09h).
This offset is compared to the crystal oscillator
frequency taking into account any programmed
calibration from registers 3C & 3D.
cnfg_upper_threshold_0
Description
upper_threshold_0_value
The Leaky Bucket type activity monitor operates on
a 128 ms cycle. If, during a cycle, it detects that an
input has either failed or has been erratic, then for
each cycle in which this occurs, the accumulator is
incremented by 1, and for each period of 1, 2, 4, or
8 cycles, as programmed in register 53h, in which
this does not occur, the accumulator is
decremented by 1.
When the accumulator count reaches the value
programmed as the upper_threshold_0_value, the
activity monitor raises an input inactivity alarm.
Bit 6
Bit 6
Bit 5
Bit 5
Description
Description
upper_threshold_0_value
Bit 4
Bit 4
Page 56
FINAL
DPLL_soft_limit_value
(R/W) Register to program the
soft frequency limit of the two
DPLLs. Exceeding this limit will
have no effect beyond triggering
a flag.
(R/W) Register to program the
activity alarm setting limit for
Leaky Bucket Configuration 0.
00000001
11111111
Bit Value
Bit Value
Bit 3
Bit 3
to
0
1
-
Value Description
Phase lost/locked determined normally.
Phase lost force when DPLL tracks to hard limit.
To calculate the ppm offset multiply this 7-bit
value by 0.628 ppm. The limit is symmetrical
about zero. A value of 0001110 bin is equivalent
to ±8.79 ppm.
Value Description
Value at which the Leaky Bucket will raise an
inactivity alarm.
ACS8514 SETS Buddy
Bit 2
Bit 2
Default Value
Default Value
Bit 1
Bit 1
DATASHEET
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1000 1110
0000 0110
Bit 0
Bit 0