MPC8572ECLPXATLD datasheet(43/140 Pages) FREESCALE

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MPC8572E PowerQUICC III Integrated Processor Hardware Specifications, Rev. 4

Freescale Semiconductor

Ethernet: Enhanced Three-Speed Ethernet (eTSEC)

When operating in SGMII mode, the eTSEC EC_GTX_CLK125 clock is not required for this port. Instead,

SerDes reference clock is required on SD2_REF_CLK and SD2_REF_CLK pins.

8.3.1

DC Requirements for SGMII SD2_REF_CLK and SD2_REF_CLK

The characteristics and DC requirements of the separate SerDes reference clock are described in

Section 15, “High-Speed Serial Interfaces (HSSI).”

8.3.2

AC Requirements for SGMII SD2_REF_CLK and SD2_REF_CLK

Table 36 lists the SGMII SerDes reference clock AC requirements. Note that SD2_REF_CLK and

SD2_REF_CLK are not intended to be used with, and should not be clocked by, a spread spectrum clock

source.

Table 36. SD2_REF_CLK and SD2_REF_CLK AC Requirements

Symbol

Parameter Description

Min

Typical

Max

Units

Notes

tREF

REFCLK cycle time

—

10 (8)

—

tREFCJ

REFCLK cycle-to-cycle jitter. Difference in the period of any two

adjacent REFCLK cycles

——

100

—

tREFPJ

Phase jitter. Deviation in edge location with respect to mean edge

location

–50

—

Note:

1. 8 ns applies only when 125 MHz SerDes2 reference clock frequency is selected through cfg_srds_sgmii_refclk during POR.

MPC8572ECLPXATLD Datasheet(PDF) 43 Page - Freescale Semiconductor, Inc