Intel IXP46X Manual do Utilizador descarregar pdf (Página 99)

Intel

IXP45X and Intel

IXP46X Product Line of Network Processors

February 2007 HDD

Document Number: 305261, Revision: 004 99

DDR-SDRAM—Intel

IXP45X and Intel

IXP46X Product Line of Network Processors

The simulation results in Figure 44 are for the control circuit and show that the voltage

waveform meets the DDR device input voltage requirements. V

il(max)

of V

ref

– 0.310 or

940 mV and V

ih(min)

of V

ref

+ 0.310 or 1.56 V are easily achieved at the receiver

(DDR_DEVICE1). The receiver waveform must also not exceed a maximum voltage of

in(max)

= 2.8 V or the minimum voltage of V

in(min)

= -0.3 V.

Waveform results for DDR_DEVICE2 and DDR_DEVICE3 are not shown as it is identical

to that of DDR_DEVICE1 due to symmetry. When final routing data is available,

simulation results for all receivers are analyzed as variations in routing may result in

differences. These differences should be minimal.

Figure 44. DDR RAS Simulation Results: Two-Bank x16 Devices

1 2 ... 94 95 96 97 98 99 100 101 102 103 104 ... 107 108

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