write time budget for DDR2

HiI am calculating the Data write time budget for DDR2 interface.I referred the following document.http://download.micron.com/pdf/technotes/ddr2/tn_47_01.pdf  Please refer the table 10 on page number 20.I am trying to understand the procedure to calculate the INTERCONNECT skew.1.  How to calculate the following        a.             Input capacitance matching        b.             REFF mismatch        c.             Input eye reduction (VREF)2.            On what basis, +/- 3.75% is considered for REFF mismatch? Isthis value related to the tolerance of resistor divider used to generateVref? 10 ps is mentioned against REFF mismatch. How do they arrive thisvalue? What slew rate value is considered?3.             â??±20mV included in DRAM skew; additional = (±25mV)/ (1.0V/ns); this includes DQ and DQSâ? â??comments against the Input eye reduction(VREF).  How do they arrive at ±25mV ? Is the value 1.0 V/ns taken fromsimulation?-- Best Regards,Balamanikandan.K
kbmanick 7 years 4 months 15 days

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