mpc8378 Freescale Semiconductor, Inc, mpc8378 Datasheet - Page 83

• Manufacturer Part Number: mpc8378
• Description: Powerquicc Ii Pro Processor
• Manufacturer: Freescale Semiconductor, Inc

21.2.3
The following list provides information about interfacing with other differential signaling levels.
Freescale Semiconductor
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•
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SD n _REF_CLK
SD n _REF_CLK
With on-chip termination to SGND_SRDSn (xcorevss), the differential reference clocks inputs are
HCSL (high-speed current steering logic) compatible DC-coupled.
Many other low voltage differential type outputs like LVDS (low voltage differential signaling) can
be used but may need to be AC-coupled due to the limited common mode input range allowed
(100 mV to 400 mV) for DC-coupled connection.
LVPECL outputs can produce signal with too large amplitude and may need to be DC-biased at
clock driver output first, then followed with series attenuation resistor to reduce the amplitude, in
addition to AC-coupling.
Figure 54. Differential Reference Clock Input DC Requirements (External AC-Coupled)
Interfacing With Other Differential Signaling Levels
SD n _REF_CLK
SD n _REF_CLK
MPC8377E PowerQUICC II Pro Processor Hardware Specifications, Rev. 3
Figure 55. Single-Ended Reference Clock Input DC Requirements
200 mV < Input Amplitude or Differential Peak < 800 mV
400 mV < SD n _REF_CLK Input Amplitude < 800 mV
High-Speed Serial Interfaces (HSSI)
150
fdafdV
V
V
max
min
> V
< V
max
cm
cm
0 V
< V
– 400m V
+ 400 mV
cm
Vcm
+ 400 mV
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