mpc8568e Freescale Semiconductor, Inc, mpc8568e Datasheet - Page 38

• Manufacturer Part Number: mpc8568e
• Description: Mpc8568e Powerquicc Iii Processor
• Manufacturer: Freescale Semiconductor, Inc

Ethernet Interface and MII Management
38
At recommended operating conditions with LV
Duty cycle for 10BASE-T and 100BASE-TX
Rise time (20%–80%)
Fall time (20%–80%)
EC_GTX_CLK125 clock rise time (20%-80%)
EC_GTX_CLK125 clock fall time (80%-20%)
EC_GTX_CLK125 duty cycle
Notes:
1. Note that, in general, the clock reference symbol representation for this section is based on the symbols RGT to
2. This implies that PC board design will require clocks to be routed such that an additional trace delay of greater than
3. For 10 and 100 Mbps, t
4. Duty cycle may be stretched/shrunk during speed changes or while transitioning to a received packet's clock domains
5. Guaranteed by characterization
6. EC_GTX_CLK125 is used to generate GTX_CLK for the eTSEC transmitter with 2% degradation. EC_GTX_CLK125
represent RGMII and RTBI timing. For example, the subscript of t
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).
1.5 ns will be added to the associated clock signal.
as long as the minimum duty cycle is not violated and stretching occurs for no more than three t
transitioned between.
duty cycle can be loosen from 47/53% as long as the PHY device can tolerate the duty cycle generated by the eTSEC
GTX_CLK.
MPC8568E/MPC8567E PowerQUICC III™ Integrated Processor Hardware Specifications, Rev. 0
Table 34. RGMII and RTBI AC Timing Specifications (continued)
RGT
6
scales to 400 ns ± 40 ns and 40 ns ± 4 ns, respectively.
DD
of 2.5 V ± 5%.
3, 4
t
t
RGTH
G125H
t
t
t
t
RGTR
RGTF
G125R
G125F
/t
/t
RGT
G125
5
5
5
RGT
represents the TBI (T) receive (RX) clock. Note
40
—
—
—
—
47
0.75
0.75
0.75
0.75
50
RGT
Freescale Semiconductor
of the lowest speed
1.5
1.5
1.5
1.5
60
53
ns
ns
ns
ns
ns
%