Agere Systems Inc.
167
Data Sheet
May 2001
and Packet Payload Engine
Ambassador T8110 PCI-Based H.100/H.110 Switch
15 Electrical Characteristics
(continued)
If an oscillator is used (see Section 7.4.4 on page 79), the signal has to be connected to the XTAL1_IN pin.
XTAL1_OUT must be left unconnected in this configuration. XTAL1_IN and XTAL1_OUT are not 5 V tolerant. The
oscillator must meet the requirements shown below.
15.2.2 XTAL2 Crystal
XTAL2 is an optional crystal oscillator input. If a crystal is used, it has to be a 6.176 MHz or a 12.352 MHz crystal
and must be connected between the XTAL2_IN and the XTAL2_OUT pins, as shown in the diagram below. Exter-
nal 24
pF, 5% capacitors must be connected from XTAL2_IN and XTAL2_OUT to Vss. The ±32 ppm tolerance is
the suggested value if the oscillator is used as the clocking source while mastering the bus. Otherwise, a crystal
with a lesser tolerance can be used (see Table 121).
If XTAL2 is not used, XTAL2_IN should be tied to V
DD
and XTAL2_OUT should be left unconnected.
* 120
maximum for 6.176 MHz crystal.
24 pF for 6.176 MHz crystal also.
18 pF for 6.176 MHz crystal also.
If an oscillator is used (see Section 7.5.1 on page 81), the signal has to be connected to the XTAL2_IN pin.
XTAL2_OUT must be left unconnected in this configuration. XTAL2_IN and XTAL2_OUT are not 5 V tolerant. The
oscillator must meet the requirements shown below.
Table 120. 16.384 MHz
Oscillator Requirements
Parameter
Value
Frequency
Maximum Rise or Fall Time
Minimum Pulse Width
16.384 MHz
10 ns, 10%—90% V
DD
Low
20 ns
High
20 ns
Table 121. XTAL2 Specifications
Parameter
Value
Frequency
Oscillation Mode
Effective Series Resistance
Load Capacitance
Shunt Capacitance
Frequency Tolerance and Stability
12.352 MHz
Fundamental, parallel resonance
75*
maximum
18
pF
7 pF maximum
32 ppm
5-6390d
Table 122. 6.176 MHz/12.352
MHz Oscillator Requirements
Parameter
Value
Value
Frequency
Maximum Rise or Fall Time
Minimum Pulse Width
6.176 MHz
12.352 MHz
10 ns, 10%—90% V
DD
Low
27 ns
10 ns, 10%—90% V
DD
Low
54 ns
High
54 ns
High
27 ns
V
SS
24 pF
24 pF
1 M
T8110
XTAL2_IN
XTAL2_OUT
12.352 MHz
CRYSTAL