mpc8555e Freescale Semiconductor, Inc, mpc8555e Datasheet - Page 30

• Manufacturer Part Number: mpc8555e
• Description: Mpc8555e Powerquicc Iii Processor With Integrated Security
• Manufacturer: Freescale Semiconductor, Inc

Ethernet: Three-Speed, MII Management
8.2.5
Table 26
30
At recommended operating conditions with LV
Data to clock output skew (at transmitter)
Data to clock input skew (at receiver)
Clock cycle duration
Duty cycle for 1000Base-T
Duty cycle for 10BASE-T and 100BASE-TX
Rise and fall times
Notes:
1. Note that, in general, the clock reference symbol representation for this section is based on the symbols RGT to represent
2. The RGMII specification requires that PC board designer add 1.5 ns or greater in trace delay to the RX_CLK in order to
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
5. Guaranteed by characterization.
6. Guaranteed by design.
7. Signal timings are measured at 0.5 and 2.0 V voltage levels.
RGMII and RTBI timing. For example, the subscript of t
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).
meet this specification. However, as stated above, this device functions with only 1.0 ns of delay.
long as the minimum duty cycle is not violated and stretching occurs for no more than three t
transitioned between.
MPC8555E PowerQUICC™ III Integrated Communications Processor Hardware Specification, Rev. 4.2
presents the RGMII and RTBI AC timing specifications.
RGMII and RTBI AC Timing
Parameter/Condition
3
RGT
4
scales to 400 ns ± 40 ns and 40 ns ± 4 ns, respectively.
Table 26. RGMII and RTBI AC Timing Specifications
2
DD
of 2.5 V ± 5%.
3
t
RGTR
t
t
RGTH
RGTH
Symbol
t
RGT
t
SKRGT
SKRGT
6,7
t
Specifications
RGT
,
/t
/t
t
represents the TBI (T) receive (RX) clock. Note also that the
RGT
RGT
RGTF
6
5
1
6
6
6,7
–500
Min
1.0
7.2
45
40
—
Typ
8.0
50
50
—
—
0
RGT
of the lowest speed
Freescale Semiconductor
Max
0.75
500
2.8
8.8
55
60
Unit
ps
ns
ns
ns
%
%