Intel GD82559ER manual Timing Specifications, Clocks Specifications, PCI Clock Specifications

Networking Silicon — GD82559ER

10.4Timing Specifications

10.4.1Clocks Specifications

10.4.1.1PCI Clock Specifications

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
0.475VCC
0.4VCC
0.325V CC
	0.2VCC
T_high	T_low
	T_cyc

0.4VCC p-to-p

(minimum)

		Figure 26. PCI Clock Waveform
		Table 22. PCI Clock Specifications
	Symbol	Parameter	Min	Max	Units	Notes
T1	Tcyc	CLK Cycle Time	30		ns	1
T2	Thigh	CLK High Time	11		ns
T3	Tlow	CLK Low Time	11		ns
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 peak-to-peak portion of the clock waveform as shown in Figure 26.

10.4.1.2X1 Specifications

X1 serves as a signal input from an external crystal or oscillator. Table 23 defines the 82559ER requirements from this signal.

Table 23. X1 Clock Specifications

	Symbol		Parameter	Min	Typical	Max	Units	Notes
T8	Tx1_dc	X1	Duty Cycle	40%		60%
T9	Tx1_pr	X1	Period		40		ns	±50PPM

Datasheet 77