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Electrical Characteristics
MPC8536E PowerQUICC III Integrated Processor Hardware Specifications, Rev. 5
Freescale Semiconductor
55
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.
2.9.3.1
DC Requirements for SGMII SD2_REF_CLK and SD2_REF_CLK
2.9.3.2
AC Requirements for SGMII SD2_REF_CLK and SD2_REF_CLK
This table lists the SGMII SerDes reference clock AC requirements. Please 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 38. SD2_REF_CLK and SD2_REF_CLK AC Requirements
Symbol
Parameter Description
Min
Typical
Max
Units Notes
tREF
REFCLK cycle time
—
10 (8)
—
ns
1
tREFCJ REFCLK cycle-to-cycle jitter. Difference in the period of any two adjacent
REFCLK cycles
—
100
ps
—
tREFPJ Phase jitter. Deviation in edge location with respect to mean edge location
–50
—
50
ps
2,3
Notes:
1. 8 ns applies only when 125 MHz SerDes2 reference clock frequency is selected via cfg_srds_sgmii_refclk during POR.
2. In a frequency band from 150 kHz to 15 MHz, at BER of 10E-12.
3. Total peak-to-peak deterministic jitter “Dj” should be less than or equal to 50 ps.