PPC8567ECVTAQJGA datasheet(66/139 Pages) FREESCALE

66 / 139 page

MPC8568E/MPC8567E PowerQUICC III Integrated Processor Hardware Specifications, Rev. 1

Freescale Semiconductor

High-Speed Serial Interfaces (HSSI)

13.2.3

Interfacing With Other Differential Signaling Levels

•

With on-chip termination to SCOREGND, 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 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.

NOTE

Figure 44 to Figure 47 below are for conceptual reference only. Due to the

fact that clock driver chip's internal structure, output impedance and

termination requirements are different between various clock driver chip

manufacturers, it is very possible that the clock circuit reference designs

provided by clock driver chip vendor are different from what is shown

below. They might also vary from one vendor to the other. Therefore,

Freescale Semiconductor can neither provide the optimal clock driver

reference circuits, nor guarantee the correctness of the following clock

driver connection reference circuits. The system designer is recommended

to contact the selected clock driver chip vendor for the optimal reference

circuits with the MPC8568 SerDes reference clock receiver requirement

provided in this document.

PPC8567ECVTAQJGA Datasheet(PDF) 66 Page - Freescale Semiconductor, Inc