mpc8544e Freescale Semiconductor, Inc, mpc8544e Datasheet - Page 69

• Manufacturer Part Number: mpc8544e
• Description: Mpc8544e Powerquicc Iii Integrated Processor
• Manufacturer: Freescale Semiconductor, Inc

Figure 49
assumes that the DC levels of the clock driver chip is compatible with MPC8544E SerDes reference clock
input’s DC requirement.
Figure 50
Since LVDS clock driver’s common mode voltage is higher than the MPC8544E SerDes reference clock
input’s allowed range (100 to 400mV), AC-coupled connection scheme must be used. It assumes the
LVDS output driver features 50-Ω termination resistor. It also assumes that the LVDS transmitter
establishes its own common mode level without relying on the receiver or other external component.
Figure 51
Since LVPECL driver’s DC levels (both common mode voltages and output swing) are incompatible with
MPC8544E SerDes reference clock input’s DC requirement, AC-coupling has to be used.
Freescale Semiconductor
HCSL CLK Driver Chip
LVDS CLK Driver Chip
Total 50 Ω. Assume clock driver’s
output impedance is about 16 Ω.
Clock Driver
Clock Driver
Clock Driver
Clock Driver
Figure 49. DC-Coupled Differential Connection with HCSL Clock Driver (Reference Only)
Figure 50. AC-Coupled Differential Connection with LVDS Clock Driver (Reference Only)
shows the SerDes reference clock connection reference circuits for HCSL type clock driver. It
shows the SerDes reference clock connection reference circuits for LVDS type clock driver.
shows the SerDes reference clock connection reference circuits for LVPECL type clock driver.
CLK_Out
CLK_Out
CLK_Out
CLK_Out
CLK_Out
MPC8544E PowerQUICC III Integrated Processor Hardware Specifications, Rev. 4
33 Ω
10 nF
10 nF
33 Ω
Preliminary—Subject to Change Without Notice
Clock driver vendor dependent
source termination resistor
100 Ω differential PWB trace
100 Ω differential PWB trace
Freescale Confidential Proprietary
SDn_REF_CLK
SDn_REF_CLK
SDn_REF_CLK
SDn_REF_CLK
50 Ω
50 Ω
High-Speed Serial Interfaces (HSSI)
50 Ω
50 Ω
MPC8544E
SerDes Refer.
CLK Receiver
SerDes Refer.
CLK Receiver
MPC8544E
Figure 51
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