MPC8548E Freescale, MPC8548E Datasheet - Page 16

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

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Input Clocks
4.3
Table 6
the MPC8548E.
4.4
When the PCI/PCI-X controller is configured for asynchronous operation, the reference clock for the
PCI/PCI-x controller is not the SYSCLK input, but instead the PCIn_CLK.
PCI/PCI-X reference clock AC timing specifications for the MPC8548E.
16
At recommended operating conditions (see
EC_GTX_CLK125 frequency
EC_GTX_CLK125 cycle time
EC_GTX_CLK125 rise and fall time
EC_GTX_CLK125 duty cycle
Notes:
1. Rise and fall times for EC_GTX_CLK125 are measured from 0.5 and 2.0 V for L/TV
2. Timing is guaranteed by design and characterization.
3. EC_GTX_CLK125 is used to generate the GTX clock TSEC n _GTX_CLK for the eTSEC transmitter with 2% degradation.
PCI n _CLK frequency
PCI n _CLK cycle time
PCI n _CLK rise and fall time
PCI n _CLK duty cycle
Notes:
1. Rise and fall times for SYSCLK are measured at 0.6 and 2.7 V.
2. Timing is guaranteed by design and characterization.
L/TV
EC_GTX_CLK125 duty cycle can be loosened from 47/53% as long as the PHY device can tolerate the duty cycle generated
by the TSEC n _ GTX_CLK. See
100Base-T reference clock.
DD
provides the eTSEC gigabit reference clocks (EC_GTX_CLK125) AC timing specifications for
= 3.3 V.
eTSEC Gigabit Reference Clock Timing
PCI/PCI-X Reference Clock Timing
Parameter/Condition
Parameter/Condition
MPC8548E PowerQUICC™ III Integrated Processor Hardware Specifications, Rev. 4
1000Base-T for RGMII, RTBI
L/TVDD = 2.5 V
L/TVDD = 3.3 V
Table 6. EC_GTX_CLK125 AC Timing Specifications
Section 8.2.6, “RGMII and RTBI AC Timing Specifications,”
Table 7. PCI n _CLK AC Timing Specifications
GMII, TBI
Table
t
PCIKHKL
2) with OV
t
t
PCIKH
G125R
t
G125H
Symbol
f
t
Symbol
PCICLK
PCICLK
f
t
G125
G125
, t
/t
, t
/t
PCIKL
PCICLK
G125F
G125
DD
= 3.3 V ± 165 mV
Min
Min
7.5
0.6
45
47
16
40
—
—
—
.
Typ
125
Typ
1.0
—
—
—
—
—
8
DD
= 2.5 V, and from 0.6 and 2.7 V for
Table 7
for duty cycle for 10Base-T and
Max
0.75
Max
133
1.0
2.1
55
53
60
60
—
—
provides the
Freescale Semiconductor
MHz
MHz
Unit
Unit
ns
ns
ns
ns
%
%
Notes
Notes
2, 3
1, 2
—
—
—
1
2