MPC8548E Freescale, MPC8548E Datasheet - Page 36

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

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Enhanced Three-Speed Ethernet (eTSEC)
A timing diagram for TBI receive appears in
8.2.6
Table 32
36
Data to clock output skew (at transmitter)
Data to clock input skew (at receiver)
Clock period
Duty cycle for 10BASE-T and 100BASE-TX
Rise time (20%–80%)
Fall time (20%–80%)
Notes:
1. In general, the clock reference symbol representation for this section is based on the symbols RGT to represent RGMII and
2. This implies that PC board design will require clocks to be routed such that an additional trace delay of greater than 1.5 ns
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 as long
5. Guaranteed by characterization.
6. In rev 1.0 silicon, due to errata, t
.
RTBI timing. For example, the subscript of t
(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).
will be added to the associated clock signal.
as the minimum duty cycle is not violated and stretching occurs for no more than three t
between.
document.
presents the RGMII and RTBI AC timing specifications.
RCG[9:0]
3
RX_CLK
RGMII and RTBI AC Timing
MPC8548E PowerQUICC™ III Integrated Processor Hardware Specifications, Rev. 4
Parameter/Condition
Figure 16. TBI Single-Clock Mode Receive AC Timing Diagram
RGT
scales to 400 ns ± 40 ns and 40 ns ± 4 ns, respectively.
t
TRRH
Table 32. RGMII and RTBI AC Timing Specifications
SKRGT
t
2
TRRDVKH
t
TRRX
is -650 ps (min) and 650 ps (max). Please refer to “eTSEC 10” in the device errata
3, 4
RGT
represents the TBI (T) receive (RX) clock. Note also that the notation for rise
Figure
Valid Data
Specifications
16.
t
RGTH
Symbol
t
t
SKRGT
t
t
SKRGT
t
RGTR
RGTF
RGT
/t
RGT
5
5
5
5
t
1
TRRDXKH
5
–500
Min
1.0
7.2
45
—
—
6
t
TRRF
RGT
of the lowest speed transitioned
Typ
8.0
50
—
—
—
0
Freescale Semiconductor
t
TRRR
500
Max
0.75
0.75
2.8
8.8
55
6
Unit
ps
ns
ns
ns
ns
%