Intel IXP45X Computer Hardware User Manual


 
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
V
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