ds3102 Maxim Integrated Products, Inc., ds3102 Datasheet - Page 85

• Manufacturer Part Number: ds3102
• Description: Stratum 3 Timing Card Ic With Synchronous Ethernet Support
• Manufacturer: Maxim Integrated Products, Inc.

Register Name:
Register Description:
Register Address:
Bit #
Name
Default
Bits 7 to 0: Holdover Frequency (HOFREQ[7:0]). The full 19-bit HOFREQ[18:0] field spans this register,
and HOCR3. HOFREQ is a two’s-complement signed integer, and it expresses the holdover frequency as an offset
with respect to the master clock frequency (see Section 7.3). Writing this field sets the T0 DPLL’s manual holdover
frequency, which is used when MANHO = 1 in the
HOFREQ field returns the manual holdover value previously written. When RDAVG = 1, reading the HOFREQ field
returns the T0 DPLL’s averaged frequency, either the fast average (if HOCR3:FAST = 1) or the slow average (if
FAST = 0). The HOFREQ field has the same size and format as the FREQ[18:0] field (FREQ1, FREQ2, and
FREQ3
offset in ppm is equal to HOFREQ[18:0] × 0.0003068. See Section 7.7.1.6.
Note: After either HOCR3:RDAVG or HOCR3:FAST is changed, system software must wait at least 50µs before
reading the corresponding holdover value from the HOFREQ[18:0] field.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
Bits 7 to 0: Holdover Frequency (HOFREQ[15:8]). See the
Rev: 012108
____________________________________________________________________________________________ DS3102
registers) to allow software to read FREQ, filter the value, and then write to HOFREQ. Holdover frequency
7
0
7
0
6
0
6
0
HOCR1
Holdover Configuration Register 1
3Eh
HOCR2
Holdover Configuration Register 2
3Fh
5
0
5
0
HOFREQ[15:8]
MCR3
4
HOFREQ[7:0]
0
4
0
HOCR1
register. When HOCR3:RDAVG = 0, reading the
0
0
3
3
register description.
2
0
2
0
1
0
1
0
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HOCR2
0
0
0
0