mpc8378e Freescale Semiconductor, Inc, mpc8378e Datasheet - Page 23

• Manufacturer Part Number: mpc8378e
• Description: Powerquicc Ii Pro Processor Hardware Specifications
• Manufacturer: Freescale Semiconductor, Inc

8
This section provides the AC and DC electrical characteristics for the enhanced three-speed Ethernet
controller.
8.1
Each SGMII port features a 4-wire AC-coupled serial link from the dedicated SerDes1 interface of the
MPC8378E as shown in
pin of the SerDes transmitter differential pair features 50-Ω output impedance. Each input of the SerDes
receiver differential pair features 50-Ω on-die termination to SGND_SRDSn (xcorevss). The reference
circuit of the SerDes transmitter and receiver is shown in
When an eTSEC port is configured to operate in SGMII mode, the parallel interface’s output signals of
this eTSEC port can be left floating. Also, when operating in SGMII mode, the eTSEC EC_GTX_CLK125
clock is not required for this port. Instead, the SerDes reference clock is required on L1_SD_REF_CLK
and L1_SD_REF_CLK pins.
8.2
The electrical characteristics specified here apply to serial gigabit media independent interface (SGMII),
media independent interface (MII), reduced gigabit media independent interface (RGMII), reduced ten-bit
interface (RTBI), reduced media independent interface (RMII) signals, management data input/output
(MDIO) and management data clock (MDC).
Freescale Semiconductor
Ethernet: Enhanced Three-Speed Ethernet (eTSEC)
SGMII Interface Electrical Characteristics
Enhanced Three-Speed Ethernet Controller (eTSEC)
(10/100/1000 Mbps)—SGMII/MII/RGMII/RTBI/RMII DC Electrical
Characteristics
SGMII SerDes
Interface
Figure 7. 4-Wire AC-Coupled SGMII Serial Link Connection Example
MPC8378E PowerQUICC II Pro Processor Hardware Specifications, Rev. 3
Transmitter
Figure
Receiver
7, where C
50 Ω
50 Ω
50 Ω
50 Ω
SD_TX n
TX
SD_RX n
SD_TX n
SD_RX n
is the external (on board) AC-coupled capacitor. Each output
C
C
TX
TX
Figure
C
C
TX
TX
SD_RX m
SD_RX m
Ethernet: Enhanced Three-Speed Ethernet (eTSEC)
65.
SD_TX m
SD_TX m
50 Ω
50 Ω
50 Ω
50 Ω
Receiver
Transmitter
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