mpc8379e Freescale Semiconductor, Inc, mpc8379e Datasheet - Page 27

• Manufacturer Part Number: mpc8379e
• Description: Powerquicc Ii Pro Processor Hardware Specifications
• Manufacturer: Freescale Semiconductor, Inc

Figure 10
Freescale Semiconductor
At recommended operating conditions with LV
EC_GTX_CLK125 reference clock period
EC_GTX_CLK125 reference clock duty cycle
measured at 0.5 × LV
Note:
1
2
3
4
5
Note that, in general, the clock reference symbol representation for this section is based on the symbols RGT to represent
RGMII and RTBI timing. Note also that the notation for rise (R) and fall (F) times follows the clock symbol that is being
represented. For symbols representing skews, the subscript is skew (SK) followed by the clock that is being skewed (RGT).
This implies that PC board design will require clocks to be routed such that an additional trace delay of greater than 1.5 ns
will be added to the associated clock signal.
For 10 and 100 Mbps, t
Duty cycle may be stretched/shrunk during speed changes or while transitioning to a received packet's clock domains as long
as the minimum duty cycle is not violated and stretching occurs for no more than three t
between
This symbol represents the external EC_GTX_CLK125 and does not follow the original signal naming convention.
provides the AC test load for eTSEC.
Parameter/Condition
DD1
MPC8379E PowerQUICC II Pro Processor Hardware Specifications, Rev. 3
Table 28. RGMII and RTBI AC Timing Specifications (continued)
RGT
Output
scales to 400 ns ± 40 ns and 40 ns ± 4 ns, respectively.
DD
of 2.5 V ± 5%.
Figure 10. eTSEC AC Test Load
Z
0
t
= 50 Ω
G125H
Symbol
t
G12
/t
G125
1
Min
47
—
R
Ethernet: Enhanced Three-Speed Ethernet (eTSEC)
L
= 50 Ω
Typical
8.0
—
RGT
LVDD/2
of the lowest speed transitioned
Max
53
—
Unit
ns
%
Notes
—
5
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