Intel IXP46X Computer Hardware User Manual


 
Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors
February 2007 HDD
Document Number: 305261, Revision: 004 95
DDR-SDRAM—Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors
The data-circuit simulation results in Figure 40 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 are not shown as it is identical to that of device
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 40. DDR Data Write Simulation Results: Two-Bank x16 Devices