MPC8548E Freescale, MPC8548E Datasheet - Page 135

• Manufacturer Part Number: MPC8548E
• Description: Integrated Processor
• Manufacturer: Freescale

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21.10 Guidelines for High-Speed Interface Termination
21.10.1 SerDes Interface Entirely Unused
If the high-speed SerDes interface is not used at all, the unused pin should be terminated as described in
this section.
The following pins must be left unconnected (float):
The following pins must be connected to GND:
Pins V28 and M26 must be tied to XV
resistor.
In Rev 2.0 silicon, POR configuration pin cfg_srds_en on TSEC4_TXD[2]/TSEC3_TXD[6] can be used
to power down SerDes block.
21.10.2 SerDes Interface Partly Unused
If only part of the high-speed SerDes interface pins are used, the remaining high-speed serial I/O pins
should be terminated as described in this section.
The following pins must be left unconnected (float) if not used:
The following pins must be connected to GND if not used:
Freescale Semiconductor
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SD_TX[7:0]
SD_TX[7:0]
Reserved pins T22, T23, M20, M21
SD_RX[7:0]
SD_RX[7:0]
SD_REF_CLK
SD_REF_CLK
SD_TX[7:0]
SD_TX[7:0]
Reserved pins: T22, T23, M20, M21
SD_RX[7:0]
SD_RX[7:0]
SD_REF_CLK
SD_REF_CLK
It is recommended to power down the unused lane through SRDSCR1[0:7]
register (offset = 0xE_0F08) (This prevents the oscillations and holds the
receiver output in a fixed state.) that maps to SERDES lane 0 to lane 7
accordingly.
MPC8548E PowerQUICC™ III Integrated Processor Hardware Specifications, Rev. 4
DD
. Pins V27 and M25 must be tied to GND through a 300-Ω
NOTE
System Design Information
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