Networking Silicon — GD82559ER
The 82559ER uses the PCI Clock signal directly. Figure 26 shows the clock waveform and required measurement points for the PCI Clock signal. Table 22 summarizes the PCI Clock specifications.
0.6VCC |
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0.475VCC |
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0.4VCC |
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0.325V CC |
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| 0.2VCC |
T_high | T_low |
| T_cyc |
0.4VCC
(minimum)
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| Figure 26. PCI Clock Waveform |
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| Table 22. PCI Clock Specifications |
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| Symbol | Parameter | Min | Max | Units | Notes |
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T1 | Tcyc | CLK Cycle Time | 30 |
| ns | 1 |
T2 | Thigh | CLK High Time | 11 |
| ns |
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T3 | Tlow | CLK Low Time | 11 |
| ns |
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T4 | Tslew | CLK Slew Rate | 1 | 4 | V/ns | 2 |
NOTES:
1.The 82559ER will work with any PCI clock frequency up to 33 MHz.
2.Rise and fall times are specified in terms of the edge rate measured in V/ns. This slew rate is met across the minimum
X1 serves as a signal input from an external crystal or oscillator. Table 23 defines the 82559ER requirements from this signal.
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| Parameter | Min | Typical | Max | Units | Notes |
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T8 | Tx1_dc | X1 | Duty Cycle | 40% |
| 60% |
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T9 | Tx1_pr | X1 | Period |
| 40 |
| ns | ±50PPM |
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Datasheet | 77 |