MPC8569E datasheet(91/127 Pages) FREESCALE

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Serial RapidIO (SRIO)

MPC8569E PowerQUICC III Integrated Processor Hardware Specifications, Rev. 1

Freescale Semiconductor

(RD and RD). Each signal swings between A volts and B volts where A > B. Using these waveforms, the definitions are as

follows:

The transmitter output signals and the receiver input signals TD, TD, RD, and RD each have a peak-to-peak swing of

A – B volts

The differential output signal of the transmitter, VOD, is defined as VTD – VTD

The differential input signal of the receiver, VID, is defined as VRD – VRD

The differential output signal of the transmitter and the differential input signal of the receiver each range from A – B

to –(A – B) volts

The peak value of the differential transmitter output signal and the differential receiver input signal is A – B volts

The peak-to-peak value of the differential transmitter output signal and the differential receiver input signal is

× (A – B) volts

Figure 47. Differential Peak-Peak Voltage of Transmitter or Receiver

To illustrate these definitions using real values, consider the case of a CML (current mode logic) transmitter that has a common

mode voltage of 2.25 V and each of its outputs, TD and TD, has a swing that goes between 2.5 and 2.0 V. Using these values,

the peak-to-peak voltage swing of the signals TD and TD is 500 mV p-p. The differential output signal ranges between 500 and

–500 mV. The peak differential voltage is 500 mV. The peak-to-peak differential voltage is 1000 mV p-p.

2.11.2

Equalization

With the use of high speed serial links, the interconnect media will cause degradation of the signal at the receiver. Effects such

as inter-symbol interference (ISI) or data dependent jitter are produced. This loss can be large enough to degrade the eye opening

at the receiver beyond what is allowed in the specification. To negate a portion of these effects, equalization can be used. The

most common equalization techniques that can be used are:

•

Pre-emphasis on the transmitter

•

A passive high pass filter network placed at the receiver. This is often referred to as passive equalization.

•

The use of active circuits in the receiver. This is often referred to as adaptive equalization.

Differential Peak-to-Peak = 2

× (A – B)

A Volts

TD or RD

B Volts

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