ds3104 Maxim Integrated Products, Inc., ds3104 Datasheet - Page 75

• Manufacturer Part Number: ds3104
• Description: Ds3104 Line Card Timing Ic With Synchronous Ethernet Support
• Manufacturer: Maxim Integrated Products, Inc.

Register Name:
Register Description:
Register Address:
Bit #
Name
Default
Bit 7: Lock T4 to T0 (LKT4T0). When this bit is set to 1 (and T0CR1:T4APT0 = 0) all output clocks are generated
from the T0 DPLL, and the T4CR1:T4FREQ field selects the frequency of the T4 APLL. See Section 7.8.2.2. When
LKT4T0 = 0, the T4 APLL can be locked to either the T4 DPLL or the T0 DPLL, depending on the setting of
T0CR1:T4APT0.
Bits 3 to 0: T4 DPL Force Selected Reference (T4FORCE[3:0]). This field provides a way to force a specified
input clock to be the selected reference for the T4 DPLL. Internally this is accomplished by forcing the clock to have
the highest priority (as specified in PTAB1:REF1). Since the T4 DPLL always operates in revertive mode, the
forced clock automatically becomes the selected reference (as specified in PTAB1:SELREF) as well.
When a reference is forced, the activity monitor for that input continues to operate and affect the relevant ISR,
VALSR
switch to another input clock. See Section 7.6.3.
Rev: 012108
________________________________________________________________________________________ DS3104-SE
0 = T4 APLL can lock to either T4 or the T0 DPLL.
1 = T4 APLL always locked to the T0 DPLL.
0000 = Automatic source selection (normal operation)
0001 = Force to IC1
0010 = Force to IC2
0011 = Force to IC3
0100 = Force to IC4
0101 = Force to IC5
0110 = Force to IC6
0111 = {unused value}
1000 = Force to IC8
1001 = Force to IC9
1010–1110 = {unused value}
1111 = Automatic source selection (normal operation)
and
MSR
LKT4T0
7
0
register bits. However, when the reference is declared invalid, the T4 DPLL is not allowed to
—
6
0
MCR4
Master Configuration Register 4
35h
—
5
0
—
4
0
3
0
T4FORCE[3:0]
2
0
1
0
75 of 136
0
0